I have a 87 trans am, it came with a 305 tbi, and the guy I got it from took that out and put in a 357 carbed motor. I was wondering what do I need parts wise for a 305 TPI switch, I have a 700r4 trans. I can get the motor, ecm, wire harness, throttle cable, cruise control, complete air cleaner and tubes, and the mass air sensor for $600. Is there anything else I need?? Also is there anything I need to do to the ecm? The ecm is from a 88 trans am, and the motor is from a 87 trans am.. Both same size motors (305 TPI)... And in case anyone is wondering, the 357 is a 87 block, with a flat tappet cam, he put re builder pistions (.040) in there, and didn't do machine work to the block, so I'm 45 thousands piston to deck clearance, without the head gasket... I do have a lot of useable parts though from it... I was hoping if it wasn't to troublesome, with the tpi setup, I could always pull off the tpi, and put on my performer intake and carb... is the in-tank fuel pump the same on a 305, and a 350?? Any suggestions...

Just to let you know I did read the sticky's, but it seems everyone switches from tbi/tpi to carb, not the other way around...

 

https://www.thirdgen.org/forums/tech...formation.html



https://www.thirdgen.org/forums/tpi/...-tpi-swap.html
https://www.thirdgen.org/forums/engi...i-350-tpi.html
https://www.thirdgen.org/forums/engi...-tpi-swap.html

Need a 350 tune in the ECM , 350 injectors and 350 knock sensor
https://www.thirdgen.org/forums/engi...swap-need.html

 

Need a 350 tune in the ECM , 350 injectors and 350 knock sensor

Why would I need a 350 tune on the ecm, if it's a 305 motor... Maybe I didn't clarify, I am buying a complete running 305 tpi motor... with the harness and ecm for a 305 tpi... The 305 motor already has the injectors, and knock sensor in it...

 

You mentioned a 357 , thought you were keeping that as most would

 

LOL, I would love to, but with it being .040 over already, I'm not sure if it's worth it to have it machined... That's why I said I'm probably the only one that wants to go from a 357, to a 305... I like the idea of tpi, that way i don't have to tinker with a carb.. BUT, if I have to I could throw my vortec intake and carb on the 305.. I'm not building a race car, just a everyday driver... I'm just looking at this from a money view point... Say I get a 350 block, then I would more then likely need to have it machined, new pistons, rods, crank, to get to a 9.0:1, or 9.5:1 for a decent everyday street car with my 64cc heads... Then I would need to get a good roller cam, and we know them aren't cheap... I'm getting a 305 tpi motor (complete), with wire harness and ecm for a 305 tpi (the 305 is from a 87 trans am, and the harness and ecm is from a 88 trans am), and the throttle cable, cruise control, complete air cleaner and tubes, and the mass air sensor for $600. I'm just wondering what else I would need to make the switch as my car was originally a tbi car, converted to carb... I always built carb cars, with no computer (60's-70's), I never messed with a say newer cars with ecm's and all these sensors... 79 and up...