BlackRabbitZ28

I have a 1991 305 TPI 5-speed Z28 Camaro. I'm going to swap a 350 TPI into it. Now I know I'll have to do something to the computer for more fuel etc.. My question is should I just swap the computer out with one from a 350 or can I use my existing computer and put a chip or reprogram it what ever? Which would be my best route and or my cheapest route to go? Is using my existing computer even an option?

Thanks for the help. I did search but this question is kind of vague answers.

techno101

If the stock ECM in your car is for a 305 TPI, if I'm not mistaken, it will work for a 350 TPI. 1990-1992 305 and 350 camaros used the same ECM-1227730.


Where abouts Louisiana are you from?

techno101

You will need to swap your injectors too, probably go to 24 lb injectors. This is stock for 350 injectors, your 305 has 19 lb injectors.

five7kid

iTrader: (14)

22 lb/hr was factory stock for 350's.

Get yourself PROM burning equipment and software. Since the '91 system is speed density, it is sensitive to every little change. If you have the capability to do your own programming, you're miles ahead.

BlackRabbitZ28

Ahh, so I can use my computer but only if I use the 1990-1992 350 motor. That will make it a little more difficult to find an engine. I would probably be better off getting the computer with it. The engine i'm looking at getting is 400 bux but its a complete engine so injectors will be included. Its going to be a highmileage long block, but i'm going to rebuild it.

BlackRabbitZ28

Shreveport/Bossier City. I actually live on Barksdale AFB.

five7kid

iTrader: (14)

Nobody said that.

3rdGenSS

you wont be able to use the memcal from the 305 for the 350.. the speed density pcm has the esc on the memcal.. the actual computer is the same for the 3.1 v-6 , 5.0 and 5.7... different memcals for each.. so you can swap the motor to a 5.7, and use your wireing and pcm... just have to change the memcal, knock sensor, and injectors.. and you are set..

techno101

Barksdale huh? I lived in Leesville, right next to Fort Polk for 20 something years. Finally had to get out of there. Live in Arkansas now.

And no you don't need then entire motor, you just need the 90-92 intake setup (speed density). If you keep everything pretty much stock you shouldn't have too many problems at all with the swap.

3rdGenSS

ok to clarify a little on what you need and what you need to do.. I have done this exact swap on my 91 z28...

you will need a 350 block and heads preferably 87+ ... then you can bolt your tpi intake you have on the 305 to the 350 engine... use the same wireing harness you have and hooke it up the same way it was on your 305...

what needs changed is... the knock sensor in the side of the block.. need one from a 91 SD setup... need to change the injectors to either an L98 injector or even an LT1 injector...
then you will need to change the memcal chip in the computer you have now.. the acutall computer is the same.. just the chip is different... you will not be able to reprogram the 305 chip for the 350 though because the SD setups had the ESC and limp home mode on the memcal and the 305 and 350 are different.. so get one from a 91-92 SD 5.7 car and put it in.. then you should be set from there...

BlackRabbitZ28

Hey guys thanks that helps a lot. Changing the knock sensor is not really a big deal. I'd like to change out a lot of the sensors anyways because the wires tend to get corodded and briddle and break and such from being out in the junk yard. I understand a lot more about the computer now again, thank you.

My best bet would probably to just buy an aftermarket chip from a 5.7 correct? I mean I want one anyways because I have heard they help a lot. So no use buying a stock one and then later on buying an aftermarket one. Anything I replace I'd like to upgrade while i'm already replacing it. So the swap doesn't seem to bad at all. I'll be picking up the engine here shortly once I get a little money. Its not going to be going in for a while though. I want a cam, headers and to rebuild it at very minimum. I'd like to get some head work done also. While i'm rebuilding it i'll probably upgrade the internals. Do that through out summer, come winter time i'll drop it in and have everything ready to go by next summer. Then start saving for the tranny since mine wont last long with an upgraded 5.7.