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Re: How to: 305 To 350 swap....everything you need to know
He im going to be doing this swap later next year and i am gathering parts for it so I just want to know if this is the proper ecu/esc that will allow me to do it..
Re: How to: 305 To 350 swap....everything you need to know
ok im getting ready to order a crate 350 from summit to go into my 92 rs 25th anniv. the factory 305 is gone..so I need at 92 caprice ecm and chip,knock sensor and esc for 350.a 350 throttle body and a fuelpump for tpi?
Re: How to: 305 To 350 swap....everything you need to know
Hello !! Guys ! I'm new on this I don't know to much of mechanic I really need ur help I just buy a car 1991 canaro rs tbi with 305 but I put another engine from 1991 suburban 350 (5.7 l) I need more power but I'm confuse 😅 cz some body tell me that is a bad engine I don't know but the machanic , he just put the same parts of 305 to 350 n somebody tell me I have to put some diferent parts like : ingectors 350,knock sensor 350, esc module 350, fuel pump tbi , n the most important 350 chip so I want order a chip but I don't k ow wich one !! N I want know if u can help me whit ur opinion what I have to do for more power on my car like what parts n number parts n where I can find them please
Or it some body recommend any mods or something tnk u so much !!
Re: How to: 305 To 350 swap....everything you need to know
I have an 85 and a 350 was already swapped "in" however no one can tell me how I am supposed to get AC. I am being told there's nowhere to put the components for air (heat doesn't work either). Anything advise will be appreciated. Where do I start?
Re: How to: 305 To 350 swap....everything you need to know
Hey guys I'm trying to do the same thing with an 89 Camaro rs 305 and 1996 GMC Vandura with a 350 it has much less miles than my car. I picked up the van for a good deal and would like to put the van engine and transmission into my car. Will I be able to steal all the parts off the van I will need to make it work? Thanks for any help.
Ps side note what should I do to the engine while it is out?
Re: How to: 305 To 350 swap....everything you need to know
Originally Posted by BMmonteSS
Ok, my head just exploded from the bajillion’th 305 to 350 swap question. So I’m going to compile some info here and just post a link from now on. You more experienced guys feel free to add or correct me where I’m wrong.
The age old 305 to 350 swap is probably one of the most popular swaps. Here is a list of items you need to make the swap, followed by an explanation of why you need them.
WHAT WILL WORK ON BOTH ENGINES:
Intake
Throttle body (the truck TB’s might have different throttle cable hookups, but otherwise are identical to the car variants)
Injector pod (although it’s easier to swap the whole 305 pod for the 350 pod)
Exhaust
Distributor
Accessories
ECM (as long as it’s a 746’)
Flex plate
Starter
WHY YOU NEED WHAT YOU NEED:
INJECTORS: Stock 305 injectors are 55 lb/hr, stock 350 injectors are 61 lb/hr, if you use 305 injectors with a 350 ecm the computer will think it has the stock 350 injectors and run lean. Get these from a junk yard or check e-bay.
KNOCK SENSOR: The knock sensors are different because they are tuned for the bore size of each motor. Get this from the junk yard or any parts store (I suggest new because they’re easy to damage taking them out).
ESC MODULE: Tuned for knock sensor and engine. Get this from a junk yard, e-bay, or any parts store. In a pinch you can get by with the 305 module, but I don’t suggest it.
CHIP: This is the most important part, the ECM is a speed density system which means it relies heavily on calculations to inject the proper amount of fuel. One of the bases of those calculations is the cylinder size and injector size. If you use a 305 computer and injectors on a 350 it is going to run LEAN because the ecm thinks there are 50 less cubic inches than there really are. If you just throw 350 injectors on there it will throw the whole tune back to the rich side because you will then have injectors that are much bigger than the ECM thinks it’s controlling. It won’t balance out with a 305 ecm and 350 injectors.
WHERE TO GET YOUR CHIP: The 746’ ecm was used in F-Bodies and Caprices, you could only get a 350 with TBI in the caprice. So you need to get your chip for a caprice, the “cop car” chip is popular because it has the speed limiter deleted and is set up for the larger cop car 65 lb/hr injectors, you’ll just have to source the cop car injectors (try eBay). A lot of people here get their chips from TBI chips or some other mail order company. I’m personally against giving these people money, but they cost about the same as a stock chip from GM ($80-120$) and you get some basic things done like the speed limiter delete, more timing, and unfortunately more fuel at WOT (you actually need much less). If you are going to be doing any major modifications to your 350 at the time of install or in the future, you may want to consider getting the chip burning equipment. It cost in the neighborhood of $120-$150 and you’ll be good to go for any modifications in the future. I’ll supply you with a 350 bin file (I’ll even make some “performance modifications”), or you can download them from one of the many sites that have them (Moates.net, tunerpro, ect.)
A word about the stock fuel pump, the stock camaro fuel pump is almost inadequate from the factory. So there is a good possibility that your 100,000 mile stocker might not be able to keep up with the added fuel demand of the 350 at high rpm’s. If you replace it go with a TPI pump or a walbro 190, your regulator will cycle the extra fuel volume back to the tank. Remember the regulator determines your pressure, the pump simply provides the volume.
Anything I missed? Anything need expanded on?
please bear with me, I've only been working on cars for 43 years. How does the ecm know the size of the injectors when there is only 2 wires going into each injector? The positive stays constant hot while running. The controlling signal is the ground in the ecm because the heat from 12 volt would cause problems. cWhen the o2 sensor detects too much oxygen, it tells the ecm to send more fuel. And my experience with the chips, I have my fuel pump set up so when the ignition is on, the fuel pump keeps running. A chip stops the pump from being shut down at 110 mph. As for the timing, you can advance the timing with the engine shut down. Advanced timing makes the engine run hotter, thus the need for a cooler thermostat which is recommended with the chip. Dropping a long block truck 350 tbi in place of a 305 should be fairly straight foward
Re: How to: 305 To 350 swap....everything you need to know
I have a 1983 Z-28 that originally came with the 305 and Crossfire Injection. The car was switched over to a Edelbrock 4-barrel and HEI ignition when I got it. The motor is tired and needs work.
I picked up a 1991 camaro with a 350 and TBI recently overhauled with a mild cam before hitting a deer.
What I'm trying to figure out is what would it take to put the whole TBI set up and distributor in my 1983 with the 350? It runs so nice right now I hate to split it up. Also, the tranny in the 91 was just overhauled and beefed up. I'm hoping to swap both the engine and tranny at the same time.
I do have the Edelbrock 650 on an Wieland Excelerator intake if needed.
Re: How to: 305 To 350 swap....everything you need to know
hi all
greetings all from the land down under of Australia, please don't hold this against me ha ha. I new hear so hear goes. I have a 1975 HJ Holden primer with a TPI 305 th700 and a 4pin LSD 3.9 diff. we have deleted the smog gear and run headers now, the th700 has a stage 2 shift kit and a 3500 stall. as you can image its a little different in a older car over hear and gets a few looks of surprise.
my question is am i able to do a crate motor swap to a 300hp 350 ? im not looking for a race or a drag car but a nice cruise machine. any help would be much appreciate, the TPI is not a common swap in Australia. I love the look of the TPI.
thank you
Re: How to: 305 To 350 swap....everything you need to know
Originally Posted by BMmonteSS
Ok, my head just exploded from the bajillion’th 305 to 350 swap question. So I’m going to compile some info here and just post a link from now on. You more experienced guys feel free to add or correct me where I’m wrong.
The age old 305 to 350 swap is probably one of the most popular swaps. Here is a list of items you need to make the swap, followed by an explanation of why you need them.
WHAT WILL WORK ON BOTH ENGINES:
Intake
Throttle body (the truck TB’s might have different throttle cable hookups, but otherwise are identical to the car variants)
Injector pod (although it’s easier to swap the whole 305 pod for the 350 pod)
Exhaust
Distributor
Accessories
ECM (as long as it’s a 746’)
Flex plate
Starter
WHY YOU NEED WHAT YOU NEED:
INJECTORS: Stock 305 injectors are 55 lb/hr, stock 350 injectors are 61 lb/hr, if you use 305 injectors with a 350 ecm the computer will think it has the stock 350 injectors and run lean. Get these from a junk yard or check e-bay.
KNOCK SENSOR: The knock sensors are different because they are tuned for the bore size of each motor. Get this from the junk yard or any parts store (I suggest new because they’re easy to damage taking them out).
ESC MODULE: Tuned for knock sensor and engine. Get this from a junk yard, e-bay, or any parts store. In a pinch you can get by with the 305 module, but I don’t suggest it.
CHIP: This is the most important part, the ECM is a speed density system which means it relies heavily on calculations to inject the proper amount of fuel. One of the bases of those calculations is the cylinder size and injector size. If you use a 305 computer and injectors on a 350 it is going to run LEAN because the ecm thinks there are 50 less cubic inches than there really are. If you just throw 350 injectors on there it will throw the whole tune back to the rich side because you will then have injectors that are much bigger than the ECM thinks it’s controlling. It won’t balance out with a 305 ecm and 350 injectors.
WHERE TO GET YOUR CHIP: The 746’ ecm was used in F-Bodies and Caprices, you could only get a 350 with TBI in the caprice. So you need to get your chip for a caprice, the “cop car” chip is popular because it has the speed limiter deleted and is set up for the larger cop car 65 lb/hr injectors, you’ll just have to source the cop car injectors (try eBay). A lot of people here get their chips from TBI chips or some other mail order company. I’m personally against giving these people money, but they cost about the same as a stock chip from GM ($80-120$) and you get some basic things done like the speed limiter delete, more timing, and unfortunately more fuel at WOT (you actually need much less). If you are going to be doing any major modifications to your 350 at the time of install or in the future, you may want to consider getting the chip burning equipment. It cost in the neighborhood of $120-$150 and you’ll be good to go for any modifications in the future. I’ll supply you with a 350 bin file (I’ll even make some “performance modifications”), or you can download them from one of the many sites that have them (Moates.net, tunerpro, ect.)
A word about the stock fuel pump, the stock camaro fuel pump is almost inadequate from the factory. So there is a good possibility that your 100,000 mile stocker might not be able to keep up with the added fuel demand of the 350 at high rpm’s. If you replace it go with a TPI pump or a walbro 190, your regulator will cycle the extra fuel volume back to the tank. Remember the regulator determines your pressure, the pump simply provides the volume.
Anything I missed? Anything need expanded on?
so- what would be the optimum engine to salvage /rebuild and install? I want to retain the TPI set-up. I was thinking of sourcing a 1986 Vette. Retain my 700R4 but maybe look at the rear gear ratio's on the vette.
Re: How to: 305 To 350 swap....everything you need to know
Originally Posted by tripple D could someone please point me in the wright direction please, im looking for a NEW TPI harness, im told i ned a hot rod harness, but im not sure. my 305tpi is in a 1975 model car. and im in AUSTRALIA the land down under. Iv tried to search e-bay. Any help would be much appreciation
THANK YOU
Re: How to: 305 To 350 swap....everything you need to know
what im looking to do is, its easier to get my hands on a stock 350 with 270-300hp. The 305 has 220-240 hp. do i still have to change it all over ? as the HP is only about say 50hp ? im not looking for a race car just a nice cruzzer. any help would be much appreciated as im in AUSTRALIA. Thank you
Re: How to: 305 To 350 swap....everything you need to know
the ecm can't tell what size injectors you have. It will get signals on how much fuel to send from the o2 sensor. Should be a straight forward change. Your tranny should bilt right up
Re: How to: 305 To 350 swap....everything you need to know
Originally Posted by Sir ian
can anybody shed some great light on this swap if i'm doing it carbureted
-choice of exhaust
-carb
-will it need a fuel pump
-headers
i have a 1991 Camaro RS
3.73 Gears with Detroit Trutrac posi
1. Hooker 2055 or Dyno Don shorties if you have an auto. 3" catback of choice.
2. Carb...lots like the Quadrajet, others like holley. 650 if you go Holley or Edelbrock or Demon or whatever.
3. It will not need a fuel pump. It will need a return style fuel regulator like Mallory 4309 or 4307.
4. See number 1...
Re: How to: 305 To 350 swap....everything you need to know
Originally Posted by Sir ian
i have an automatic, it came with a flowmaster american thunder with factory y pipe what needs to be changed when swapping the 350 in?
As far as the exhaust? Nothing...305 and 350 are exactly the same physically. Only change what you want to change. Check out the exhaust forum for ideas.
Re: How to: 305 To 350 swap....everything you need to know
Originally Posted by Biggd4355
please bear with me, I've only been working on cars for 43 years. How does the ecm know the size of the injectors when there is only 2 wires going into each injector? The positive stays constant hot while running. The controlling signal is the ground in the ecm because the heat from 12 volt would cause problems. cWhen the o2 sensor detects too much oxygen, it tells the ecm to send more fuel. And my experience with the chips, I have my fuel pump set up so when the ignition is on, the fuel pump keeps running. A chip stops the pump from being shut down at 110 mph. As for the timing, you can advance the timing with the engine shut down. Advanced timing makes the engine run hotter, thus the need for a cooler thermostat which is recommended with the chip. Dropping a long block truck 350 tbi in place of a 305 should be fairly straight foward
How does the ecm know the difference between the 350 ijeectors and the 305 injectors? The injectors operate from a grounding signal sent from the ecm. In closed loop the o2 sensor will detect oxygen, if there is too much it will send more pulses sending more fuel. So how does the o2 sensor tell the difference?
Re: How to: 305 To 350 swap....everything you need to know
Originally Posted by BMmonteSS
Ok, my head just exploded from the bajillion’th 305 to 350 swap question. So I’m going to compile some info here and just post a link from now on. You more experienced guys feel free to add or correct me where I’m wrong.
The age old 305 to 350 swap is probably one of the most popular swaps. Here is a list of items you need to make the swap, followed by an explanation of why you need them.
WHAT WILL WORK ON BOTH ENGINES:
Intake
Throttle body (the truck TB’s might have different throttle cable hookups, but otherwise are identical to the car variants)
Injector pod (although it’s easier to swap the whole 305 pod for the 350 pod)
Exhaust
Distributor
Accessories
ECM (as long as it’s a 746’)
Flex plate
Starter
WHY YOU NEED WHAT YOU NEED:
INJECTORS: Stock 305 injectors are 55 lb/hr, stock 350 injectors are 61 lb/hr, if you use 305 injectors with a 350 ecm the computer will think it has the stock 350 injectors and run lean. Get these from a junk yard or check e-bay.
KNOCK SENSOR: The knock sensors are different because they are tuned for the bore size of each motor. Get this from the junk yard or any parts store (I suggest new because they’re easy to damage taking them out).
ESC MODULE: Tuned for knock sensor and engine. Get this from a junk yard, e-bay, or any parts store. In a pinch you can get by with the 305 module, but I don’t suggest it.
CHIP: This is the most important part, the ECM is a speed density system which means it relies heavily on calculations to inject the proper amount of fuel. One of the bases of those calculations is the cylinder size and injector size. If you use a 305 computer and injectors on a 350 it is going to run LEAN because the ecm thinks there are 50 less cubic inches than there really are. If you just throw 350 injectors on there it will throw the whole tune back to the rich side because you will then have injectors that are much bigger than the ECM thinks it’s controlling. It won’t balance out with a 305 ecm and 350 injectors.
WHERE TO GET YOUR CHIP: The 746’ ecm was used in F-Bodies and Caprices, you could only get a 350 with TBI in the caprice. So you need to get your chip for a caprice, the “cop car” chip is popular because it has the speed limiter deleted and is set up for the larger cop car 65 lb/hr injectors, you’ll just have to source the cop car injectors (try eBay). A lot of people here get their chips from TBI chips or some other mail order company. I’m personally against giving these people money, but they cost about the same as a stock chip from GM ($80-120$) and you get some basic things done like the speed limiter delete, more timing, and unfortunately more fuel at WOT (you actually need much less). If you are going to be doing any major modifications to your 350 at the time of install or in the future, you may want to consider getting the chip burning equipment. It cost in the neighborhood of $120-$150 and you’ll be good to go for any modifications in the future. I’ll supply you with a 350 bin file (I’ll even make some “performance modifications”), or you can download them from one of the many sites that have them (Moates.net, tunerpro, ect.)
A word about the stock fuel pump, the stock camaro fuel pump is almost inadequate from the factory. So there is a good possibility that your 100,000 mile stocker might not be able to keep up with the added fuel demand of the 350 at high rpm’s. If you replace it go with a TPI pump or a walbro 190, your regulator will cycle the extra fuel volume back to the tank. Remember the regulator determines your pressure, the pump simply provides the volume.
Anything I missed? Anything need expanded on?
Hey I'm just starting to get into engine building and swaps as I just got a 91 camaro RS with a 305. No power and 230000 miles haha. So im planning on dropping a 99 vortec 350 in, and you covered mostly everything. But I still don't know, will anything have to be fabricated to put the engine in? Do the motor mounts mount up the same way as the 305? Also if I'm planning to do a mild build should I rebuild the engine? Or should the stock bearings pistons, etc. Be good enough?
Re: How to: 305 To 350 swap....everything you need to know
HI i have a 350 that i want to put in my 88 formula 305 tbi 700r4 the engine has lt1 pistons unknown alloy heads . i need to put a cam in this put the tbi on it and make it run .im a electronics idiot i would not know whear to start with messing with chips etc ive looked in to the tbi mods can do that no problem put larger injectors yep get that fule pump im with ya .PROM whot the ! lost need a idiots guide .HELP
Re: How to: 305 To 350 swap....everything you need to know
From what I understand, you are limited on the cam size because of the tbi. I've been told carburetor is the way to go for a big cam, but that includes distributor and I'm not sure about the transmission linkage
Re: How to: 305 To 350 swap....everything you need to know
Biggd4355 that is whot i have been told will be the easy way round it but not sure if air con and cruse will work if ecu dun away with also gear box converter lock gets screwed up
Re: How to: 305 To 350 swap....everything you need to know
Nobody ever delt with the t5 WC parts comparability. 95truck TBI into a 89rs 305tbi body. I check part numbers on the 350 flywheel and they are different than the 305. Do I keep the 350 fly or change to the 305. Or if I go with a l98 motor I have what flywheel do I put on it and clutch kit. Somebody's gotta know!
Re: How to: 305 To 350 swap....everything you need to know
HI bobby im no expert but hear is whot i have found .two difrent flywheels one for early two piece oil seal and one for late one piece seal.thay also run difrent starter motors stagard or straight bolt patern .if u puting a 350 in id guess use the flywheel on yore motor and corect startor the cluch is sumint i dont know .surely sumone like hawks may be able to help .ow the flywheels are difrent diameter but bellhousing stud patern the same.hope this helps .
Re: How to: 305 To 350 swap....everything you need to know
It dose help. My car didn't have a motor flywheel clutch pressure plate or inspection cover. For the most part everything else is there. From what ur saying though if I order a 305 flywheel to fit the t5 Tran and get a good clutch set I could get things moving
Re: How to: 305 To 350 swap....everything you need to know
I did this swap.i went with a 96 350 vortec.i used the flywheel and the starter from the Camaro stock 305.but when I went to start it I could starter come out but it sounds like it's hitting a tooth on the starter and it drains the battery after one try...
Re: How to: 305 To 350 swap....everything you need to know
Originally Posted by dctrumpet
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!
What are the part numbers of all the compatible ESC modules for 350's?
- I got a 92 camaro that I just swapped the 305 L03 tbi with a 350 L98 from a 89 firebird but kept it TBI. It's an automatic also if that matters. Still running the same ECM from the L03. I just need to find the right part number for a 350 ESC module so I can order it. Any help would be greatly appreciated. Thanks in advance.
Re: How to: 305 To 350 swap....everything you need to know
so i finished my swap, but with the 91 caprice ECM my cooling fan will not turn on and neither will my ac fan system on all modes. Is there a mutual ground i may have forgotten?
Re: How to: 305 To 350 swap....everything you need to know
most early vortec motors had the spider injection weather it was the 4.3 or the 5.7 so eathier way thats completely inadiquite for talking about the 305 to the 350 TBI swap, even thugh the 5.7 looked like it had the TBI set up it really did not that was just a air intake due to the spider injection being port injected verses the TBI being simmler to a CARB and being injected from the top side
Re: How to: 305 To 350 swap....everything you need to know
Originally Posted by henryd3
Don't the caprices come with clutch fans and non-electrical fans? The ECM probably doesn't know how to turn on your electric fan
the ecm in tbi cars actually doesnt turn it on. Its quite simple actually. just a Head coolant switch between cylinders 6&8. When that reaches 220F, or what ever you switch you actually have, it triggers the fan to turn on. Then you have your actual temp gauge probe/wire between cylinders 1&3.
Re: How to: 305 To 350 swap....everything you need to know
I have an 88 camaro 305. Im buying a 350 block and a 383 stroker kit. What exactly has to get changed and added so i can make this work. This will be my first engine swap/build. I have some mechanical background but im open to everyones opinions. Thank you!! I appreciate it
Re: How to: 305 To 350 swap....everything you need to know
I did a 305 to 350 swap but now I have a delay when switching gears or I have to get to high rpm to switch gears does any one know what this problem is ?
Re: How to: 305 To 350 swap....everything you need to know
Originally Posted by Ayo_roberto
I did a 305 to 350 swap but now I have a delay when switching gears or I have to get to high rpm to switch gears does any one know what this problem is ?
I'm assuming you have an auto. Did you adjust the tv cable correctly?
Re: How to: 305 To 350 swap....everything you need to know
Good shopping list,
Everything but the my original wire harness I have 1986 IROC-Z that USED to have a 305 TPI now she's getting a 350 TPI / ZZ4 Crate Motor / .502 grind cam / Roller rockers / guides / push rods all comp cams. Everything else is goin back on smog, etc. Connection concerns with the 350 PROM?
Re: How to: 305 To 350 swap....everything you need to know
Hey Guys i know this is an 11 year old post, but I have some questions. Ok I just swapped a 350, from a 93 chevy 1500 into my 88 Firebird. Im using the knock sensor, and injectors from the 350. Im using the TBI from my 305, just with the 350's injectors in it, should that be a problem? The ESC is from my 305, as well. OK HERES THE BIG QUESTION. On the computer, I found am 87 Suburban with a 350 tbi, and used its chips(since this era ecm had two chips in it) in my old 305 computer. I wanted to know if I should replace the entire Computer "box" with a computer from a 94 1500 or should I just get my car tuned or.... Idk cause my Firebird is running alright, but I feel like she could run alot better. Lmk guys thanks
Re: How to: 305 To 350 swap....everything you need to know
Originally Posted by gavin.priestley
OK HERES THE BIG QUESTION. On the computer, I found am 87 Suburban with a 350 tbi, and used its chips(since this era ecm had two chips in it) in my old 305 computer.
If the '87 Sub and your '88 Firebird both have the OEM ECMs, your ECM is currently in limp mode. It is running the engine on backup fueling and limp mode ignition timing. The SES/CEL should also be rapidly flickering. You placed a mask $42 chip ('7747 ECM) into a mask $4D ECM ('8063). It won't like that...
I wanted to know if I should replace the entire Computer "box" with a computer from a 94 1500 or should I just get my car tuned or.... Idk cause my Firebird is running alright, but I feel like she could run alot better. Lmk guys thanks
Getting an ECM/PCM from a '94 truck opens a can of worms. It can be done but you need to know what needs to be done for it to work.
!!
