tlamm

I sure this has been been down. I just can't get all this imfo im reading together.

I plan on Swapping my 305 out of my 91 firebird with a 355. The 355 will have stock 350 heads, cam and valvetrain. Try to find specs on cam.

Can i just swap all those parts listed except I'm sure i will need a custom tune. Where can a get a custon Chip?

Just trying to figure this out.

92FBirdVert

iTrader: (1)

caprice use 965 ecm for their 350 tbi not 746, so chips wont interchange
so will the ecm completely swap out?

jahblah

this is my question. or better yet, why dont people use the ecm from a tbi truck? they are much easier to come by.

RSCAMAROGUY91

After reading almost everything on here I still have a few grey areas that don't seem to make any since on this swap. First, I read that a Caprice has the same ECM as a Camaro, then a few post later I read that they didn't have the same ECM. So my question is do they or do they not have the same ECM? IF they do that would mean that you could enter change the chips, right? Also, with all of the questions about chips and such, why could you not simply put a chip for a Z/28 in it, unless it would be too different from where it is for a TPI engine and not a TBI engine.

Steve30

So I realize this thread has been going for quite a while, but I read quite a bit of it and find my question unanswered. It seems all the swap info relates to computer controlled engines. The PO of my 84 Z converted the 305 to a carb. Given that, I plan to run a carbed 350. From what I've read in this thread, I can just drop in and not worry about all this stuff? Am I correct here? Also, the 305 was mildly built with an intake manifold, cam and new valves and springs. I assume these all can be reused since the only thing different is the cylinder bore and crank. (at least that's what I always thought). The 350 is in fact the same block, correct? Anyway, just looking for a few pointers or potential problems I'll need to pay attention to. Thanks!

Steve30

Upon re-reading some things, I realized this is located in the tbi portion of the forum, which explains why I saw nothing on carbed motors. But I'd still appreciate some info. Thanks all

RicerEater78

Yes, the 350 and the 305 are essentially the same same block. You would be able to use all of the same parts to my knowledge as long as you use the same lifters in the same spots (assuming you plan on reusing the cam). The only thing I'm not real sure on is using the same cam with different cam bearings. I've done it before, but that doesn't necessarily mean its the proper way.

Also, you would probably want to think about using different heads if they are stock. From what I've heard and seen, most 305 heads don't provide enough air to a 350.

Steve30

Sweet. Thanks man! Feeling more confident about this swap now.

RicerEater78

I mean, there are things that you should think about changing. If you change heads, you may or may not be able to use your valves and springs. Some heads have different valve sizes, lengths, etc. But for the intake and cam, no problem. You'll also want to get the card tuned.

Steve30

Yea the engine I'm getting has heads with new springs and seals so I'm gonna use them. Definitely wanna re-use my cam and lifters though. Apparently the cam that comes with the engine I'm buying has the fuel pump lobe ground off. I'm assuming that was a provision for an electric fuel pump. I have a mechanical so I'll need a different camshaft. Thanks for the info man. I've never attempted anything like this before so I'm kinda learning as I go. The new engine doesn't have any rocker arms. My 305 has roller rockers (I have no idea what kind yet, haven't looked), I assume I can use them?

one92rs

iTrader: (5)

as for why not using certain ecm's. it depends on the number that the pcm is. a 8746 and a 7747 have different ecm pinouts. some other ecm's will also have different pinouts. hence they are not plug and play. the 746 ecm a lot of people use will run a 350 with a 350 or custom chip in it.

RicerEater78

That all depends on the stud size. Different rockers will fit on different studs. Other than that, I can't imagine there being any issues, but I'm not 100%.

one92rs

iTrader: (5)

i will depend on stud size and if they are self aligning.

Seighart

ok i need clarification PLZ! im a hair confused on what i need...
i have an 86 camaro that from the harness and rpos says it had a 305 tbi. (bought car for cheap as a roller) it also has a 700r4. but i found a 350 tbi out of a 95 tahoe. the 350 is a complete motor (all stock sensors accs distributor etc..) im looking to basically go from stock to stock. from what i have read i have come to understand that i will need a new esc module and ecm(or at least a chip) but what im needing to know is what do i get them from? can i get either if not both parts from a mid 90s truck/suv with a tbi 350? or do i need to attempt to find parts out a 198?-199? caprice? if i could get the years and vehicles i need to pull from i would be happy as can be. THANKS

hatemail72

http://www.tbichips.com/ecminfo.htm

REFERENCE THE ABOVE

Seighart

ok while that does give me a wide variety of options im still at a loss. my ecm is a serv # 1227169 and i need to find out what ecm or chip i need to make the stock 350 run.(very sorry im HORRID at all this comp stuff so i have no idea what i need to get my project finished up. i have no clue what ecms will interchange here or if i need to rewire the car to fit a 746 ecm. i dont want to go off into more work than what is needed.

_______________________________________________________________
ok after a bit of research i have come to find that the 1227169 is out of a 1986 caprice 5.0 with a carb.

RicerEater78

I'm not sure how much a computer matters. km not sure what kind I have, but I know its meant for an 89 305 and it runs my 350 fine. I little low in the idle, but other than that its fine. my 350 was swapped in by the previous owner who left everything 350 except the motor. I changed the injectors, iac, and pressure regulator and all is good.

Seighart

well now that i got time to actually run down to my car and check everything over again i have come to find im on the the wrong forum now lol. the previous owner decided to do a full out carb swap and even though my rpos say it has/had a tbi setup it is now all carb all the way down to the fuse box. so im just gonna pull the intake/tb off and slap a carb and carb intake on it and call it a day. i just want the damn thing to run lol. ty all for the heads up though!

92RS4US

Was a member a few years ago but didn't remember my password and I think my profile got deleted from inactivity. Anyways back then I was building a 89 RS with a 383 that I put together with an 89 roller block from an 89 corvette, scat rotating assembly, KB forged pistons and AFR 195 heads. The stock roller cam I had reground and with 1.6 rockers it came out to .483"lift 208/218@.050" on 110 LSA. It had the Edelbrock TBI intake which I had the holes opened up and was going to use a big block ported throttle body with bigger injectors and custom chip by turbo city. Also had the Edelbrock shorty headers and it was all gonna set up to look like the factory 5.0L so it would pass smog in Ca. What sucks is I never got to finish the car, but I'm glad I didn't finish it after reading this thread. Lots of important info thanks guys for providing the info!!! I never thought about the knock sensors and the ESC module or the different PCMs. I had a new distributor ready to go and was going to use all the sensors for a 5.7L engine. This info is invaluable and will definitely use this if I decide to swap to a 5.7L TPI...but I might consider an LS1 swap.

johnf123

does anyone know where to look for injectors? I looked on Summit and only found 20 lb injectors, not 55

one92rs

iTrader: (5)

http://www.injectorwhse.com/servlet/StoreFront

i get all my injectors from here.

snick193

I have a stock 1989 firebird can I follow this guide. I new to cars so I have almost no clue on what to do. I plan on dropping in a chevy 350 bored .60 over.

jahblah

Ive swapped in the 350 (from a cop caprice) and all its goods but i was still running the firebirds 305 "computer" and "chip". it ran like a dog so i swapped over the caprice "computer" and "chip" and it ran like dog S**T!!! idle was horrible and it was completely undriveable. jurked like a lonely old man and almost stalled repeatedly. note, my firebird is a manual and the caprice was an automatic and i now know that doesnt work together...which i just read in another page of this thread..

What next?? Somebody please help a poor soul out...

jahblah

any help out there?

jahblah

anybody??

kendalljmeyer

this is impossible to figure out cause im way too new to engines.. i have a few questions.. i have a 305 TBI thats blown and i have a 350 TBI from a 1988 truck. i want to know what im going to need, with part numbers if thats possible.. thanks cause i am way lost

Ozz1967

iTrader: (4)

As long as the TBI motor from the truck was a runner...ie. It was running in the truck right before you pulled it, all it needs is to be put in your car, your intake put on, bolt up the exhaust and go. A few minor checks to make sure the timing is good and all that, but that's basically it. Now I have heard that the truck TBI units are sometimes better than the ones on our cars. So you may want to keep that. Do a search on this web site man, there is so much info to find just by reading.

RicerEater78

There are a few things that you can get away with not using. Basically what I did for mine was just change the idle air control, fuel pressure regulator, and injectors. I don't have part numbers, but do some research on what vehicles and years have the L05 motor and go to auto zone, they should be able to help you out. Changing both of those parts is easy. As for the injectors, go to a junk yard and find one of the trucks that would have used the L05 because they can be pricey new and get a rebuild kit because the rubber o-rings for those injectors usually expand once removed. just those few things and you'll have a 350 that makes a decent bit of power and (for me anyways) gets 26-27 mpg.

86chevy4x4

Ive got an 86 Chevy K10 4x with 305 with quadrajet im thinking about doing a swap with an 89 chevy 4x but this is fuel injected i need to remain carberated to pass smog i believe and i dont know to much about this kind of stuff any advise is appreciated

Superfast

Hey guys im thinking about buying my first camaro. Its a 1991 rs with the 305 tbi which i didnt think had very much power at all. Am i better off building the 305 or swapping a 350 in it? Where isa good place to get a good engine for cheap. Im 16 so i dont really have a whole lot to spend. Any and all advice is appreciated! Sorry if this is posted in the wrong spot.

Ozz1967

iTrader: (4)

I'd stick with the 305 now, especially since your budget is small. There is alot you can to to "freshen up" a 305, starting with exhaust. This means headers, 3" catback, highflow cat, good muffler, either flowmaster, Magnaflow, or hooker. This is the single best "Hp gainer" for these motors. This will run $300-$500 depending on what you get and you could see a gain of up to 30hp or so.

After this, either buying new heads, or porting and polishing your existing heads and putting a new cam in the motor. This is another $200-$500 for parts, not including labor. This is good for another 30-200hp depending on how far you go and how much $$ you have.

Jumping into a new motor, youre looking at $2000-$3000 just get get it installed and running, and that's if everything goes perfectly. Also, depending on where you live, you may or may not be able to register the vehicle when it's done due to emissions laws.

Hope this gave you some ideas on where to look!

If you jump right into a new motor,

jacksonml3

thanks for the info... regarding the throttle body, can I keep the tpi plenum from the 305? What about the transmission, can I keep that too?

zackd66

ok, I have a 85 firebird that is all oe. the 305 LG4 was rebuilt, however, giving me problems. I also have a 350 TBI chevy tahoe I want to take the motor out of and put in my firebird. I do NOT want the TBI. I want to put the 350 carbed into the firebird. I know I need a new intake manifold to match the bolt difference, but what else? change distributor to HEI? wiring ? WHAT? please help, i dont want to end up junking my baby to the first buyer....

Ozz1967

iTrader: (4)

What year Taho? Depending on the year it could be an issue with the heads and cooling (Not sure if they put an LT1 motor in the Tahoe's or not).

If the 85 is 100% there, then all you need to bring from the Tahoe is the motor so long as it's a Gen 1 style 350. You may need to port match the heads and intake (the 305 Intake will be fine for the 350, do not use the 305 heads on the 350). I'm not sure if they put the LT1 motors in the Tahoe's or not. If it's a gen 1, then your intake will bolt up to it and then all that's needed is the motor.

Since it's a 350, you would need to get a 350 knock sensor. But other than that, no other wiring would be needed as all the 305 stuff is a direct swap.

Kush Barnes

Ok , we'll what about a 305 to 350 vortec tbi swap? Everyone's telling me I need intake manifold and some other crap

Coleman Webb

I am currently doing a 305-350 swap in my 1984 Chevy van. I was going to use the old transmission but someone told me that it will not work with the 350. Is this true? Also he said I may have problems with my radiator not being able to keep up with the bigger 350 engine... Any help would be greatly appreciated.

Ozz1967

iTrader: (4)

You shouldn't have any issues. If your radiator works fine with the 305 then it'll work fine with the 350.

Now, as for the transmission, should also work fine. the only issues you might run into would be in the year of the motor, you may need a different flex plate and/or starter. What year is the 350 that you're putting in?

Coleman Webb

I had planned on buying a rebuilt motor and putting it in, basically I searched 1984 Chevy g10 van on sandjengines.com and a couple options came up, both are listed from 1980-1985 but one is a high preformance engine with a few different options, not sure what to go with, I am most interested in which will give me better fuel economy but the performance model doesn't cost much more than the regular one. My current 305 has no guts going uphill and has been diagnosed to have a possible cam issue. So I figured, ditch the old 305 and swap for a new 350 and reuse all my acessories. I'm a bit of a newbie to mechanics but I have fixed a few things on it so far and decided to attempt the swap. Thanks a lot for your help!

Ozz1967

iTrader: (4)

The van is carbed correct?

A 350 that you researched will work fine. you can re-use everything from your 305 however, I would not recommend using the heads as they will shoot your compression sky-high. Look through the "Engine build" or "engine swap" section on here for more ideas on what to do. If you want I can give you the specs on my 320hp 350 build.

Coleman Webb

Carbed yes. I am a little confused though... The crate engine has new heads allready does it not? Also any advice on the performance vs nonperformance model? I don't want to over complicate this job but the price difference is like 60 bucks. Yeah, I would love to have a look at those specs too. Thanks again.

Ozz1967

iTrader: (4)

I'm not sure of where you are getting your motor, but this is one of the best "budget" performance motors out there. Mine is very comparable to this one.

290HP Chevy 350

The crate motor should come with heads if you get the long block or "turn key" version. If you get a short block you'll only get the block, and bottom end, crank, cam, pistons, rods etc.

My 350 is a roller block from a 98 Silverado that was wrecked.

It's a

350 bored .040
Speed pro 9.3:1 hypereutectic dished pistons
World Sportsman II heads (no mods, just out of the box)
Edelbrock Performer intake
Scat rotating assembly which includes cast crank and forged I-beam rods.
Lunati 60121 cam
Comp cams Pro-magnum roller rockers.
Electronic Quadrajet factory carb (rebuilt by Cliff Ruggles)

Hooker 2055 shorty headers with a 3" catback and hooker aerochamber muffler.

I haven't had the motor dynode since getting the carb tuned however it was 240hp at the rear wheels.

Coleman Webb

Yeah I was looking at long blocks, the one I saw was just under 1200 bucks, with a 7 year warranty anyhow, I don't think I need a performance model, I'm figure the 350 will be an upgrade to what I am used to with the 305, I have pulled the motor out and stripped it down so I'm getting ready to pick up the new one and start the install. I am hoping to use my old carb, distributor and whatever else I can, so going performance might not be necessary... As I don't want to have to get a bunch more preformance parts, what do you think? The performance model does have flat top pistons, a preformance cam,194 intake valve heads, and a high volume oil pump. Being quite novice at this it doesn't mean a heck of a lot to me. Thanks again

ringo234

That motor is 290HP at the flywheel on an engine dyno with a high flow carb. Expect reduced numbers with TBI.

ringo234

I know money can be an obstacle but you get the cheapest parts on those motors. cast pitons and cranks vs, forged. Steal heads with 8.5:1 compression ratio vs aluminum head with 10.1:1 compression ratio non hardened push rods. You get what you pay for.

http://www.jegs.com/i/GM+Performance...FepZ7Aod_mYA6Q

88firebird400

Okay, I really want to do this swap. I have a complete 1991 caprice cop car with 63k miles on it. Have anyone who has done this swap from stock 305 to stock 350 what was ur ET and 1/4 mile? I run 15.800 with my 305

Also anything special I'm going to need out of the caprice?

Socomclinger

Ok have a quick ? I'm building 383 for a 91 rs with 5 speed I know I'll have to change the tbi injectors to bigger ones other than that I'm lost can this be done and keep the tbi

viperexpress

I swapped in a carb 350 in a 92 RS. Car was originally a 305 TBI. How can I get my speedo to work?

KITT1983

iTrader: (3)

That's strange, there were should be a vss wire on the tranny.

xxcamaroRSxx

hey guys sorry if im repeating this question but will older 305 heads fit my tbi 305. like these ones http://www.ebay.com/itm/SBC-Chevy-305-327-350-Aluminum-Cylinder-Heads-Angle-Plug-Complete-200cc-64cc-/390665015041?pt=Motors_Car_Truck_Parts_Accessories&hash=item5af5730f01&vxp=mtr

Ozz1967

iTrader: (4)

Will they fit? yes

However you don't really want to use 305 heads on a 350, it'll shoot our compression ratio through the roof.