Go Back  Third Generation F-Body Message Boards > Tech Boards > TBI
Reload this Page >

How to: 305 To 350 swap....everything you need to know

TBI Throttle Body Injection discussion and questions. L03/CFI tech and other performance enhancements.

How to: 305 To 350 swap....everything you need to know

Old 05-19-2008, 03:25 PM
  #151  
Senior Member
iTrader: (8)
 
88FormulaKiller's Avatar
 
Join Date: Mar 2008
Location: NH
Posts: 647
Car: 1967 Firebird P.T.
Engine: LS3 4" Strkr 422ci
Transmission: MN12 6 speed
Axle/Gears: 3.73 8.5" 10 Bolt Eaton
Re: How to: 305 To 350 swap....everything you need to know

just wanted to add some input, i have a ws6 formula that came with the 305 tbi which smoked the rings, so, i replaced it with a 350 tbi...i did Not swap anything, i bought the engine from my father whose worked for GM for 23 years so it wasnt a mistake like some people have asked me, it is a 350!...car has ran absolutely mint for over a year. no swapping.
88FormulaKiller is offline  
Old 06-02-2008, 07:32 PM
  #152  
Member
 
duderjay's Avatar
 
Join Date: May 2008
Location: calgary
Posts: 195
Car: 88 iroc z28
Re: How to: 305 To 350 swap....everything you need to know

Can the ecm out of a a 95 chevy truck fit and be used in a 88 iroc? The engine out of the truck is a 350 all done up, the prom in the truck ecm was burned by pro's on a dyno. Its a tbi.

I have a 305 tbi in my Camaro. I am being offered the whole works to throw into my camaro.

Basically I am wondering if I can use the ecm and the prom out of the truck for a short cut and just drop it into my car.

The truck rates 286 horses at the wheels. I kind of figured it would go good in the camaro for instant horsepower with out to many hassles
duderjay is offline  
Old 06-26-2008, 11:30 PM
  #153  
Member
 
Join Date: Sep 2002
Location: Wyoming, Mi
Posts: 128
Car: 89 Camaro RS Convertible
Engine: 355 chevy power
Transmission: 5 speed manual
Axle/Gears: standard
Re: How to: 305 To 350 swap....everything you need to know

just one question as i have most of this process done since my engine is older and i cannot use an aftermarket tbi intake cause they didnt make one for pre 87 heads umm where can i get the vacuum for the brake booster?
GMZombie is offline  
Old 08-02-2008, 07:22 PM
  #154  
Member
iTrader: (1)
 
Join Date: Jul 2008
Location: Fox Lake, Illinois
Posts: 204
Car: 1991 RS
Engine: 350 TBI
Transmission: 700r4
Axle/Gears: 3.08 lt. slip
Re: How to: 305 To 350 swap....everything you need to know

FYI I just completed the 305 to 350 swap. The doner was a 92 9c1 caprice to my 91 RS. In addition to keeping 350 knock sensor swaping the ESC module, I HAD to also swap the ECM's swaping just the chips worked but the car ran poorly after swaping the chips back then swaping the ECM's everything is grrreat!
Jono4820 is offline  
Old 08-13-2008, 11:53 PM
  #155  
Senior Member
 
DyingYoung138's Avatar
 
Join Date: Jun 2008
Location: Maryville, TN
Posts: 398
Car: '86 Trans Am
Engine: 305 H.O.
Transmission: 700r4
Re: How to: 305 To 350 swap....everything you need to know

I noticed most of you swap with TPI, but I have a 305 carb... would it be the same thing as what you guys say to swap a 350 carb in? I'm not that literate with all this yet, so I was curious on the matter. Would I have to mess with any timing, computers, or anything just to pull a 305 out and put in the 350, both being carb? Or what all would I do to change everything to TPI (I think TPI is more reliable and can push more hp and torque)
DyingYoung138 is offline  
Old 09-16-2008, 09:03 PM
  #156  
Junior Member
 
Join Date: Sep 2008
Location: Pennsylvania
Posts: 2
Car: 1992 Camaro RS
Engine: 305
Transmission: 700R4
Axle/Gears: 3.42
Re: How to: 305 To 350 swap....everything you need to know

I was thinking about putting a 327 in my 92 Camaro RS. Do you think I would need to change the TBI injectors or the ECM module for that? seeing it is so close to the 305 now in it.
RSCAMRS is offline  
Old 09-16-2008, 09:13 PM
  #157  
Member
 
Join Date: Jun 2007
Posts: 233
Re: How to: 305 To 350 swap....everything you need to know

As a first step you would get in the ballpark by bumping up your fuel pressure to compensate for the increased bigger inches. You need to bump it by the square of the ratio of the cubic inch increase, so assuming your stock pressure is at 11.5 psi (a typical stock TBI pressure):

New Pressure = 11.5 psi * (327/305) * (327/305) = 13.2 psi

The cheapest and easiest way to do this is to swap in a TPI fuel pump and either get one of the adjustable regulator kits (Jet, cfm-tech, xtremefi) for your TBI or take the spring out of it and use an inline external regulator and gauge (I like this way better, the conversion kits can be a pain to adjust).

For best performance you would want to do a full chip tune on the car (even if you just keep the 305) but the fuel pressure increase should get the car running ok for starters.

Paul T.
titchener is offline  
Old 09-18-2008, 01:31 PM
  #158  
Supreme Member
iTrader: (4)
 
Ozz1967's Avatar
 
Join Date: Dec 2005
Location: St. Cloud, MN
Posts: 4,733
Car: 1984 Trans Am
Engine: In progress 6.0 LS swap
Transmission: 4l60e with 3600 FTI converter
Axle/Gears: Zexel Torsen 3.73, 28-spline mosers
Re: How to: 305 To 350 swap....everything you need to know

Originally Posted by DyingYoung138 View Post
I noticed most of you swap with TPI, but I have a 305 carb... would it be the same thing as what you guys say to swap a 350 carb in? I'm not that literate with all this yet, so I was curious on the matter. Would I have to mess with any timing, computers, or anything just to pull a 305 out and put in the 350, both being carb? Or what all would I do to change everything to TPI (I think TPI is more reliable and can push more hp and torque)
I just did this 350 swap and kept the factory CC carb and distributor set up in my 84 T/A. I've run into no problems, the carb is big enough. The only thing I would really worry about now are these...

--Get new O2 sensor
--Get 350 knock sensor
--bump your timing depending on the cam...I'd say 9 or 10 with a strong cam would be just about right. I'm running a larger cam so I'm pushing 12 advanced initial timing.
--You're carb is big enough the way it is though it may run a little lean. I haven't run into any problems with mine though.

Hope this helps! If you have any questions, feel free to PM me.
Ozz1967 is offline  
Old 11-16-2008, 01:45 PM
  #159  
Member
 
Regal105's Avatar
 
Join Date: May 2008
Location: Canada, C.B.S. NL
Posts: 145
Car: 86' Camaro, 06 Vortec Max
Engine: 406, Lq9
Transmission: TH-700R4, 4L70
Axle/Gears: 3.42, 4.10
Re: How to: 305 To 350 swap....everything you need to know

has anyone ever tryed to swap a 305tbi for a 454 tbi?
Regal105 is offline  
Old 11-24-2008, 01:38 PM
  #160  
Member
 
Regal105's Avatar
 
Join Date: May 2008
Location: Canada, C.B.S. NL
Posts: 145
Car: 86' Camaro, 06 Vortec Max
Engine: 406, Lq9
Transmission: TH-700R4, 4L70
Axle/Gears: 3.42, 4.10
Re: How to: 305 To 350 swap....everything you need to know

i just have one question that really buggs me about the whole 305 to 350 swap, if tbi 350 is put into a 305 tbi car, why cant the whole 350 ecm be used? are the plugs different? please clarify
Regal105 is offline  
Old 11-24-2008, 01:45 PM
  #161  
Senior Member
iTrader: (10)
 
dctrumpet's Avatar
 
Join Date: Feb 2006
Location: Central Illinois
Posts: 736
Car: 1992 Firebird
Engine: 350 TBI W/all Ultimate TBI Mods
Transmission: 700R4
Axle/Gears: 9 Bolt 3.27
Re: How to: 305 To 350 swap....everything you need to know

Originally Posted by Regal105 View Post
i just have one question that really buggs me about the whole 305 to 350 swap, if tbi 350 is put into a 305 tbi car, why cant the whole 350 ecm be used? are the plugs different? please clarify
To make it non-complicated this is my best explanation:
The actual TBI unit is pretty much the same from a 305/350. The main difference between the 305 and 350 is the knock sensor, esc module and injectors. These sensors are based on engine displacement. That being said, the 350 requires more fuel thus requires a different "chip" than the 305. Computers can be the same, but the chips are different. You can put a 350tbi base on a 305 and not have to "tune" it as long as you put back the 305 injectors.

Not sure if this is what you were asking or not??
----------
I think I know what you were asking now that I re-read what you stated.

If you are doing a basic 350 stock install into a 305tbi vehicle you can used the stock 350 ecm and chip. As long as the 350 doesn't have any mods that require tuning

Last edited by dctrumpet; 11-24-2008 at 01:49 PM. Reason: Automerged Doublepost
dctrumpet is offline  
Old 11-25-2008, 03:28 PM
  #162  
Member
 
Regal105's Avatar
 
Join Date: May 2008
Location: Canada, C.B.S. NL
Posts: 145
Car: 86' Camaro, 06 Vortec Max
Engine: 406, Lq9
Transmission: TH-700R4, 4L70
Axle/Gears: 3.42, 4.10
Re: How to: 305 To 350 swap....everything you need to know

yeah the last part was what i was lookin for stock to stock 305 to 350 swap
Regal105 is offline  
Old 01-29-2009, 06:50 PM
  #163  
Junior Member
 
pony exp.305's Avatar
 
Join Date: Jan 2009
Posts: 12
Re: How to: 305 To 350 swap....everything you need to know

True, Best way leave TBI on 305. I am newbie here..I read a lot here relating TBI. I can't believe some of them remove TBI out for Carbed. I used to have one 1991 Camaro RS with nice 350TBI/ 310 hp for drive daily. Really strong acceleration and run over 40K miles without any problems. I decided to sold it.
Piux here:


Few weeks later, I miss to drive 1991 camaro rs. One day, I went to Appalachian Mtns for ride around. I found one 1991 Camaro, was parked under tree and very dust over car. The engine 305 TBI was not started. I bought it for $950.00 and had to tow it to my home. I found the ignition module was not good and replaced it then It started with BIG BLUE SMOKE out from exhaust.




I think about going to rebuild on engine/tranmissioon soon when I have enough money/time schedule.

Originally Posted by Lewism111 View Post
Yea a dumb question I have will everything work like gauges and what not will anything NOT work Im wondering because I have a 1980 350 Carb which Im gonna take my manifold and put it on the 350 and leave it a tbi
pony exp.305 is offline  
Old 02-10-2009, 10:16 PM
  #164  
Junior Member
 
Join Date: Dec 2008
Location: Georgetown, TX
Posts: 5
Car: 90 RS'
Engine: 305 TBI
Transmission: Automatic
Axle/Gears: 2.73
Re: How to: 305 To 350 swap....everything you need to know

so the 305 throttle body wont work on a 350 or do i need to just swap the injectors
cnnbrunson is offline  
Old 02-10-2009, 10:18 PM
  #165  
Senior Member
iTrader: (10)
 
dctrumpet's Avatar
 
Join Date: Feb 2006
Location: Central Illinois
Posts: 736
Car: 1992 Firebird
Engine: 350 TBI W/all Ultimate TBI Mods
Transmission: 700R4
Axle/Gears: 9 Bolt 3.27
Re: How to: 305 To 350 swap....everything you need to know

305 and 350 TBI are the same. Only real difference is the injectors
dctrumpet is offline  
Old 02-14-2009, 12:44 PM
  #166  
Junior Member
 
Join Date: Dec 2008
Location: Georgetown, TX
Posts: 5
Car: 90 RS'
Engine: 305 TBI
Transmission: Automatic
Axle/Gears: 2.73
Re: How to: 305 To 350 swap....everything you need to know

Does anyone know what the stock part number is for the Chip from 8746 ecm. I cant seem to find it. I just dropped a 350 into my 90 camaRO RS AND DIDNT KNOW I HAD TO CAHGE THIS STUFF. I have the injectors, knock sensor, and esc module i need, but cant find a chip!!!!!!!!!!!!!!
cnnbrunson is offline  
Old 02-14-2009, 01:05 PM
  #167  
Senior Member
iTrader: (10)
 
dctrumpet's Avatar
 
Join Date: Feb 2006
Location: Central Illinois
Posts: 736
Car: 1992 Firebird
Engine: 350 TBI W/all Ultimate TBI Mods
Transmission: 700R4
Axle/Gears: 9 Bolt 3.27
Re: How to: 305 To 350 swap....everything you need to know

Brian Harris from Harris Performance will have a number of these for you. Go to tbichips.com and his contact information is there.
dctrumpet is offline  
Old 02-14-2009, 02:28 PM
  #168  
Moderator
iTrader: (1)
 
Join Date: Mar 2002
Location: Chasing Electrons
Posts: 17,322
Car: check
Engine: check
Transmission: check
Re: How to: 305 To 350 swap....everything you need to know

Originally Posted by cnnbrunson View Post
Does anyone know what the stock part number is for the Chip from 8746 ecm. I cant seem to find it. I just dropped a 350 into my 90 camaRO RS AND DIDNT KNOW I HAD TO CAHGE THIS STUFF. I have the injectors, knock sensor, and esc module i need, but cant find a chip!!!!!!!!!!!!!!
There isn't a stock chip for a 5.7l TBI camaro. GM only offered TBI on the L03 5.0l engines in the f-body's. If you replace the stock L03 55#/hr injectors with 61#/hr injectors you are 96% of the way there.

For the other 4% it depends upon which 350 you dropped in. Heads & cams vary among the different 350's and will make a difference on how the SA and fueling should be.

Try it with the injector change and the stock chip and see how it runs. Then if there are any issues that need to be corrected in the tune you can get into DIY tuning or find someone local to take it to.

RBob.
RBob is offline  
Old 02-17-2009, 10:20 PM
  #169  
Junior Member
 
Join Date: Feb 2009
Location: Baltimore Md
Posts: 9
Car: 91 RS (In project) 350 TBI
Engine: 350 TBI Pulled From 87 Chev Truck
Transmission: stock Manual 5 speed
Axle/Gears: stock
Re: How to: 305 To 350 swap....everything you need to know

I didnt convert the engines parts I just pulled one from an older truck and replaced the 305 with the 350. The only thing i had to change was a few minor things. I think it would be cheaper and quiker to do it the way I did it.
NewJerseyMI is offline  
Old 03-02-2009, 04:22 PM
  #170  
Junior Member
 
Join Date: Dec 2008
Location: Georgetown, TX
Posts: 5
Car: 90 RS'
Engine: 305 TBI
Transmission: Automatic
Axle/Gears: 2.73
Re: How to: 305 To 350 swap....everything you need to know

Originally Posted by looneybug26 View Post
yo Paul T. i pushed and pushed on autozone, threatining with lawyers and slander until the manager finally caved and said he would give me the credit for my other chip even though he was not supposed to. lets hope this new one does the trick. thanks Paul.
Hey looney, What was the correct part # for that chip. I cant seem to find it anywhere. I Just did the 305tbi to 350tbi swap in my 90 rs and cant find the part numbers I need. What year caprice should i tell the parts store. This has been a huge headache ,but i hope its worth it
cnnbrunson is offline  
Old 03-10-2009, 02:06 PM
  #171  
Member
iTrader: (2)
 
dollarbill425's Avatar
 
Join Date: Jan 2003
Location: Missouri
Posts: 140
Car: 89 Camaro RS
Engine: 350
Transmission: T5
Axle/Gears: 3.42
Re: How to: 305 To 350 swap....everything you need to know

I did this swap 7 years ago, I dont get a lot of time to work on her but I'm still trying to find the correct part number for the caprice esc, knock sensor and chip as well......mines running rich with 305 ecm knock and esc, with 350 injectors which makes sense.... I miss driving her and need those numbers, I tried the non roller numbers and didnt come up with a for sure answer... If someone can clarify and tell us exactly what part number of esc, and knock sensor please, or am i just a dumba$$ and missed that part??

Last edited by dollarbill425; 03-10-2009 at 02:15 PM.
dollarbill425 is offline  
Old 03-10-2009, 02:20 PM
  #172  
Member
iTrader: (2)
 
dollarbill425's Avatar
 
Join Date: Jan 2003
Location: Missouri
Posts: 140
Car: 89 Camaro RS
Engine: 350
Transmission: T5
Axle/Gears: 3.42
Re: How to: 305 To 350 swap....everything you need to know

I searched autozones website and found part#s for a 91 caprice 5.7l,,,
knock sensor part# SU154 $30.99

ESC part# ESC100 73.99

Will these work for me after I get a chip burned for my 305 ecu?
dollarbill425 is offline  
Old 03-10-2009, 03:05 PM
  #173  
Senior Member
iTrader: (10)
 
dctrumpet's Avatar
 
Join Date: Feb 2006
Location: Central Illinois
Posts: 736
Car: 1992 Firebird
Engine: 350 TBI W/all Ultimate TBI Mods
Transmission: 700R4
Axle/Gears: 9 Bolt 3.27
Re: How to: 305 To 350 swap....everything you need to know

where in Missouri?
dctrumpet is offline  
Old 03-10-2009, 03:07 PM
  #174  
Senior Member
iTrader: (10)
 
dctrumpet's Avatar
 
Join Date: Feb 2006
Location: Central Illinois
Posts: 736
Car: 1992 Firebird
Engine: 350 TBI W/all Ultimate TBI Mods
Transmission: 700R4
Axle/Gears: 9 Bolt 3.27
Re: How to: 305 To 350 swap....everything you need to know

Originally Posted by gheatly View Post
I went to the GM dealer this afternoon to do some research and to order my new parts. As noted above, I found that the knock sensor and ESC module need to be paired. A 350 knock sensor should be used with a 350 ESC module. The 350 and 305 parts have different part numbers.

There are 2 ESC modules and knock sensors for 350s. For those of us without roller cams (i.e., 1984-1986 models), you need the following parts:

ESC module - GM p/n 16126761 (cost me $109.89)
knock sensor - GM p/n 10456287 (cost me $58.48)

I originally asked for parts for an '84 Vette with Crossfire. The parts guy said that these two parts work in ALL 350 applications for those year models.

1987-up engines have more knocking sounds in them due to the aggressive nature of the opening and closing ramps on the roller cam. Thus, the knock sensor is different. These year models have different part numbers.

I saw these part numbers in a post where someone was doing a 305 to 350 conversion in a 1990 Firebird. He used sensors from a 1990 Caprice 350. Those part numbers were:

ESC module - GM p/n 16128261
knock sensor - GM p/n 10456288

Give this a shot. Have you checked these numbers out?
dctrumpet is offline  
Old 03-10-2009, 03:24 PM
  #175  
Member
iTrader: (2)
 
dollarbill425's Avatar
 
Join Date: Jan 2003
Location: Missouri
Posts: 140
Car: 89 Camaro RS
Engine: 350
Transmission: T5
Axle/Gears: 3.42
Re: How to: 305 To 350 swap....everything you need to know

Central by Fort Leonard Wood 2 hours south west of STL... I tried those numbers on gmpartsdirect and some other websites and kept gettin results for 5.0l engines...those part numbers i posted I finally found from autozone using a 91 caprice
dollarbill425 is offline  
Old 03-10-2009, 03:58 PM
  #176  
Member
iTrader: (2)
 
dollarbill425's Avatar
 
Join Date: Jan 2003
Location: Missouri
Posts: 140
Car: 89 Camaro RS
Engine: 350
Transmission: T5
Axle/Gears: 3.42
Re: How to: 305 To 350 swap....everything you need to know

called chevy, they said part#s 16126761 (5.0L) and 10456287 (4.3L and also used on a 350 corvette) are both knock sensors, I'll try the other two on the bottom of your post thanks
dollarbill425 is offline  
Old 03-10-2009, 04:47 PM
  #177  
Senior Member
iTrader: (10)
 
dctrumpet's Avatar
 
Join Date: Feb 2006
Location: Central Illinois
Posts: 736
Car: 1992 Firebird
Engine: 350 TBI W/all Ultimate TBI Mods
Transmission: 700R4
Axle/Gears: 9 Bolt 3.27
Re: How to: 305 To 350 swap....everything you need to know

GM 10456288 is ACDelco 213-324. It was used in 4.3L, 5.7L and a few 7.4L GM vehicles
GM 10456287 is ACDelco 213-325. It was used in 2.3L, 3.0L, 3.8L, 4.1L. 5.0L and 5.7L

these are other OEM numbers for vehicles that had a 350.
KNOCK SENSORS
90-93 Caprice 5.7L Vin 7 GM 10456018 which is ACDelco 213-324 same as the GM 10456288
84-86 vette 5.7L vin 8 GM 10456017 which is ACDelco 213-325 same as the GM 1456287
87-89 camaro/vette 5.7L Vin 8 GM 10456018 which is ACDelco 213-324 same as the GM 10456288

Many of the 5.7L trucks used the above numbers as well. Mostly the 10456018

I am currently running the 10456018. Yes, it was also used in 4.3L vehicles as well, but predominantly the 5.7L. Who knows? LOL. GM is crazy and nothing they did ever made sense.

HOPE THIS HELPS!!!!

I will do the same for the ESC modules!

Last edited by dctrumpet; 03-10-2009 at 04:58 PM.
dctrumpet is offline  
Old 03-11-2009, 01:29 PM
  #178  
Member
iTrader: (2)
 
dollarbill425's Avatar
 
Join Date: Jan 2003
Location: Missouri
Posts: 140
Car: 89 Camaro RS
Engine: 350
Transmission: T5
Axle/Gears: 3.42
Re: How to: 305 To 350 swap....everything you need to know

thanks a lot man, i'll see if I can find them
dollarbill425 is offline  
Old 03-14-2009, 11:43 PM
  #179  
Junior Member
 
Join Date: Dec 2008
Location: Georgetown, TX
Posts: 5
Car: 90 RS'
Engine: 305 TBI
Transmission: Automatic
Axle/Gears: 2.73
Re: How to: 305 To 350 swap....everything you need to know

Thats all the numbers for everything i have. Do you have the number for the chip i need. Can you help with that. I want to get into burning my own chip, but i need this to get me running for now. Please help!!!!!!!!!!!!!! I cant find the part number for the chip I need. Everytime I call chevy they tell me they need the broadcast # for the ecm. I ask for the chip for a 92 Caprice police car.
cnnbrunson is offline  
Old 03-15-2009, 01:41 AM
  #180  
Member
iTrader: (2)
 
92Forumla's Avatar
 
Join Date: Jul 2005
Location: Jacksonville, Florida
Posts: 141
Car: 1989 GTA
Engine: LB9 305 TPI
Transmission: 700-R4
Axle/Gears: G80 3.42 gears
Re: How to: 305 To 350 swap....everything you need to know

I just bought a Complete L98 out of a 89 GTA. For $600 it comes with motor,trans,complete harness and ecu? What will I need to make it work? Car is currently a 305 TBI/700R4 '92 Camaro. Off the top of my head I can think of fuel lines, pump, and ESC. What else?
92Forumla is offline  
Old 04-23-2009, 08:24 PM
  #181  
Junior Member
 
Join Date: Aug 2006
Posts: 22
Re: How to: 305 To 350 swap....everything you need to know

hey guy i put a 350 old version with a set of vortec heads .change injector 'ecm'esc 'knock sensor ' and if i push quick on gaz it backfire in the tbi .sounds better if i advance the timing but the motor can't crank no more after ...any idea ????timing is set at 0 ....any idea about a different chip to solved that problem ???
strocker383 is offline  
Old 04-23-2009, 08:56 PM
  #182  
Junior Member
 
Fastcar92's Avatar
 
Join Date: Jun 2005
Location: Hemet, Ca.
Posts: 41
Car: 91 RS Camaro
Engine: 350
Transmission: 5 Speed
Axle/Gears: 3:08
Re: How to: 305 To 350 swap....everything you need to know

well i am using my 305 injectors but i THINK IM LOOSING HOSE POWER witout the 350 injectors
Fastcar92 is offline  
Old 04-23-2009, 09:30 PM
  #183  
Junior Member
 
Join Date: Aug 2006
Posts: 22
Re: How to: 305 To 350 swap....everything you need to know

how can i ritcher up a little .....running 12 lbs pressure gaz ..doesnt seem to be able to raise up more ....
strocker383 is offline  
Old 04-23-2009, 11:02 PM
  #184  
Supreme Member
iTrader: (4)
 
Ozz1967's Avatar
 
Join Date: Dec 2005
Location: St. Cloud, MN
Posts: 4,733
Car: 1984 Trans Am
Engine: In progress 6.0 LS swap
Transmission: 4l60e with 3600 FTI converter
Axle/Gears: Zexel Torsen 3.73, 28-spline mosers
Re: How to: 305 To 350 swap....everything you need to know

Originally Posted by strocker383 View Post
hey guy i put a 350 old version with a set of vortec heads .change injector 'ecm'esc 'knock sensor ' and if i push quick on gaz it backfire in the tbi .sounds better if i advance the timing but the motor can't crank no more after ...any idea ????timing is set at 0 ....any idea about a different chip to solved that problem ???
Please check your spelling and grammar.

It sounds like your timing is off, are you certain you put the distributor in correctly? It's really easy to have it one or two degrees off and that will screw up everything.
Ozz1967 is offline  
Old 04-24-2009, 06:31 AM
  #185  
Junior Member
 
Join Date: Aug 2006
Posts: 22
Re: How to: 305 To 350 swap....everything you need to know

yes timing is set correctly ...its set at 0 with the wire unplug ....can i raise up the fuel pressure to make it run a little ritcher ..its set at 11 1/2 psi...sounds like its lean ..it does the same thing went u put a little shooter on a holley carb..
strocker383 is offline  
Old 04-24-2009, 02:24 PM
  #186  
Supreme Member
iTrader: (4)
 
Ozz1967's Avatar
 
Join Date: Dec 2005
Location: St. Cloud, MN
Posts: 4,733
Car: 1984 Trans Am
Engine: In progress 6.0 LS swap
Transmission: 4l60e with 3600 FTI converter
Axle/Gears: Zexel Torsen 3.73, 28-spline mosers
Re: How to: 305 To 350 swap....everything you need to know

Originally Posted by strocker383 View Post
yes timing is set correctly ...its set at 0 with the wire unplug ....can i raise up the fuel pressure to make it run a little ritcher ..its set at 11 1/2 psi...sounds like its lean ..it does the same thing went u put a little shooter on a holley carb..
The best way to tell if it's lean is to get a Air/Fuel mixture monitor. That way you can monitor the rich/lean condition while you mess with your mixtures. Also, on my car (84 T/A with a computer controlled carb), I have to run the timing at 9 advanced with the plug unpluged, pulls about 32 degrees or so with it plugged in. Or take it to a shop with a dynometer than can dial it in perfectly for you on the dyno. With any kind of backfire, it's usually a timing issue of some sort. Anyone else know if a too rich/lean condition can cause a backfire? I do know that if you are running really lean it causes your computer/ecm to dump more fuel which can make you think it's running rich.
Ozz1967 is offline  
Old 06-07-2009, 07:48 PM
  #187  
Junior Member
 
Join Date: Jun 2009
Posts: 1
Re: How to: 305 To 350 swap....everything you need to know

Hello all, I am new to the board. But I have been reading this thread. WoW lots of information. I have a 2001 F-Body, I am very happy with it.

But I have a 1986 Chevy Silverado K-10 with a 305 carb that I would like to change out to a late model 350 tbi. Can this be done ? And what am I getting myself in to ?

Any advice is welcome.

Thanks,
T_N
Tough_Nuts is offline  
Old 07-11-2009, 12:03 AM
  #188  
Member
 
Join Date: May 2006
Location: east aurora, ny
Posts: 367
Car: 1989 camaro rs
Engine: 305 tbi
Transmission: 700r4
Axle/Gears: 3.23 lsd swap
Re: How to: 305 To 350 swap....everything you need to know

says starters and flexplates are the same for the 305 and 350. not entirely accurate. the 350 that i used had a larger flexplate and i had to use a different starter becuase of that larger flexplate. i used the flexplate that came with my 350. i assumed it needed a larger flexplate becuase it might have more compression, not sure why the difference
ad356 is offline  
Old 07-14-2009, 04:57 AM
  #189  
Member
 
Join Date: Nov 2008
Location: The Wild West AKA AZ
Posts: 165
Car: 87 Iroc Z
Engine: 350 TPI
Re: How to: 305 To 350 swap....everything you need to know

Sorry if this isn't the right place to put this, but I figure this is where I may be able to get my answers.

I have a question. I replaced alot of parts on my car, but currently, it runs kinda poorly. For example, sometimes when I come to a stop, the car would act as if it wants to die on me (it's died on me a few times like that). I can also warm up the car for a little bit, and afterawhile, the car would die (unless I feather the pedal a little bit). That's just the jist of it. I can post more details if need be.

I searched all over for answers, getting advice on what it could be, and so far, I think I narrowed it down, but I'm not 100% sure. As of now, I'm on a tight money budget, and I don't want to carelessly waste money on shooting arrows in the dark in hopes of a miracle cure. I'm trying to source it down and possibly solve my problem.

Here's the situation:

My car is a 87 Iroc Z, and it currently has a 350 in it, laced up with TPI. The car originally had a 305, but swapped it for the above mentioned motor. Here's what I'm starting to question. Durring the swap, the previous owner never swapped the ECM nor the corresponding chip that goes with the 350 into the new swap. I'm pretty much running a 350 on a stock 305 prom chip.


Here's a few questions I'm hoping to get answered.

1. Being that it's been running pretty poorly, could not having the 350 prom along with the proper ECM, and ESC make the car run this sluggish? I read those are required in the engine swap.

2. I know the previous owner replaced the knock sensor, but my question is, how do I identify what kind of knock sensor he might of installed? Is there different numbers, different shape, what should I be looking for?

3. I'm gunning to replace the stock 305 prom with a 350 prom (just to get it out of the way). I've been looking at hypertech and I read on here that alot of people say it's junk. In all honesty, I'm just looking for a stock replacement (not looking for any performance gains, just stock 350). Would I be better off on finding a stock one? Is hypertech even worth looking into? Or, should I just order one off of TPIparts?

When I got the car, the previous owner gave me another prom chip from TPIparts, and when it came down to installing it, it ran like chit. Could it of been that it was a defected chip, or could it of been that I didn't have the proper ESC module and "possibly" incorrect knock sensor? There was a BIG difference on how it idled with that chip. At times, it would crank, but wouldn't start. When it DID start and gave it a test drive, I couldn't even break the 45 MPH barrier. I'm leaning on a defected prom chip.

All help is appreciated. If I have to, I could post specs of the car and what has been changed on there from when the previous owner had it, to present time since I'm the current owner now.
Samurai_Of_Dawn is offline  
Old 07-16-2009, 05:17 AM
  #190  
Member
 
Join Date: Nov 2008
Location: The Wild West AKA AZ
Posts: 165
Car: 87 Iroc Z
Engine: 350 TPI
Re: How to: 305 To 350 swap....everything you need to know

Does anyone have any suggestions at all? I just wanna get the car back on the road without any problems rather than have it sit and collect dust.
Samurai_Of_Dawn is offline  
Old 08-07-2009, 04:07 PM
  #191  
Member
 
charlielamb's Avatar
 
Join Date: Jun 2008
Location: Greenville
Posts: 112
Car: 1991 formula
Engine: 350 tbi
Transmission: T-5
Axle/Gears: 308 posi
Re: How to: 305 To 350 swap....everything you need to know

im doing this swap and was wondering if i can use the chip out of a 350 tbi truck? also my car has a manual if that matters
charlielamb is offline  
Old 08-10-2009, 10:11 PM
  #192  
Junior Member
 
Join Date: Jan 2009
Posts: 11
Car: 1990 Firebird
Engine: '89 cubevan 350
Transmission: T5
Axle/Gears: 98SS 3.42
Re: How to: 305 To 350 swap....everything you need to know

Hmmmm.......

Last edited by 90poc; 08-10-2009 at 10:45 PM.
90poc is offline  
Old 08-10-2009, 10:44 PM
  #193  
Junior Member
 
Join Date: Jan 2009
Posts: 11
Car: 1990 Firebird
Engine: '89 cubevan 350
Transmission: T5
Axle/Gears: 98SS 3.42
Re: How to: 305 To 350 swap....everything you need to know

i did the 305 to 350 swap

it is a 1990 bird, manual tranny, stock computer #1228746

i had an issue with the idle surging and then it would die. the solution was to adjust the minimum air "aka" idle adjustment screw. i found instructions on this website under "IAC and TPS adjustment"

then it ran ok but i got a code (43 i think) esc or faulty computer. not having any luck with finding a '90 caprice 350 chip. i took a chance and plugged in a computer with prom from a 90 pick-up #1228747. this fixed the service engine light problem but i can definately tell im running a truck program, good lowend power and doesnt make any power above 3000rpm

im now waiting for a shipment of burning equipment from Moates
90poc is offline  
Old 08-21-2009, 07:46 PM
  #194  
Member
iTrader: (2)
 
GMODUDE's Avatar
 
Join Date: Jan 2007
Location: Cherryville, NC
Posts: 169
Car: 92 Camaro RS
Engine: 5.7L 385 Fastburn
Transmission: 700R4
Axle/Gears: 9 Bolt 3.70 Gears
Re: How to: 305 To 350 swap....everything you need to know

Yo i got a 385 fast burn crate motor and ide like to keep my tbi system if possible. The engine now has a dual plane intake manifold for carb. it has a hot cam in it and pushes over 400hp. its goin in my 92 camaro tbi 305.now is there a certain aftermarket manifold i should run or is there a way i can adapt my carb manifold to run tbi? plus where should i look to get new injectors. would i need to change fuel pumps to get the right psi? I am going to take the car to a dyno shop to get the chip made and ecm tuned but i just need to know the parts that would be specifically different being it is pushing 400hp.Ive even heard the stock 305 manifold wont fit on vortec heads....is that true?
GMODUDE is offline  
Old 09-01-2009, 12:19 PM
  #195  
Junior Member
 
NJrFirebird's Avatar
 
Join Date: Jun 2009
Location: new jersey
Posts: 21
Car: 1989 Firebird
Engine: 305
Transmission: 700r4 w/ kit
Re: How to: 305 To 350 swap....everything you need to know

little reverse here but would a 700r4 tranny from the 350 fit into a 305?
NJrFirebird is offline  
Old 09-01-2009, 01:16 PM
  #196  
Supreme Member
iTrader: (4)
 
Ozz1967's Avatar
 
Join Date: Dec 2005
Location: St. Cloud, MN
Posts: 4,733
Car: 1984 Trans Am
Engine: In progress 6.0 LS swap
Transmission: 4l60e with 3600 FTI converter
Axle/Gears: Zexel Torsen 3.73, 28-spline mosers
Re: How to: 305 To 350 swap....everything you need to know

Originally Posted by NJrFirebird View Post
little reverse here but would a 700r4 tranny from the 350 fit into a 305?
What was the other type of tranny?

Essentially yes, it'll bolt right up, minimum is a new flywheel and brackets for the kickdown and TV cables.
Ozz1967 is offline  
Old 09-01-2009, 02:42 PM
  #197  
Junior Member
 
NJrFirebird's Avatar
 
Join Date: Jun 2009
Location: new jersey
Posts: 21
Car: 1989 Firebird
Engine: 305
Transmission: 700r4 w/ kit
Re: How to: 305 To 350 swap....everything you need to know

thanks
NJrFirebird is offline  
Old 09-22-2009, 12:38 PM
  #198  
Junior Member
 
Join Date: Sep 2009
Location: Newport News, Virginia
Posts: 67
Car: 1985 Chevrolet Camaro
Engine: V8 lb9 i believe..
Transmission: 700r4
Axle/Gears: 10 bolt posi
Re: How to: 305 To 350 swap....everything you need to know

umm, i know this is a tbi board. but what if i use a carb setup. is the first post different aside from the injectors and everything else it says i need. virtually no electronics are connected to the engine.
vampyrico is offline  
Old 10-07-2009, 03:51 PM
  #199  
Supreme Member
iTrader: (6)
 
SiCkRs's Avatar
 
Join Date: Dec 2008
Location: Norwalk, CA
Posts: 2,535
Car: 91Z28
Engine: 5.7 ls1
Transmission: 4l60e
Axle/Gears: 3.42
Re: How to: 305 To 350 swap....everything you need to know

I have L98 engine block and was wondering what would i need to put it in my 91 RS its a 305 tbi right now.
SiCkRs is offline  
Old 11-18-2009, 02:16 PM
  #200  
Junior Member
 
steven hecker's Avatar
 
Join Date: Sep 2009
Posts: 16
Car: 1992 GTA
Engine: 305 TPI
Transmission: 700R4
Re: How to: 305 To 350 swap....everything you need to know

i know that with an adaptor plate i can put the tbi on a pre 85 350, but can you put vortec 350 heads on a pre 85 block?
steven hecker is offline  

Thread Tools
Search this Thread
Quick Reply: How to: 305 To 350 swap....everything you need to know


Advertising
Featured Sponsors
Vendor Directory

Contact Us - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: