Just found this site and it looks great:eek:

I've had a question for awhile now and it looks like this is where I can find the answer.

I've got a '87 Chevy p/u that had a 305 in it. An oil pump went out and eventually so did the engine so we threw in a 350. Now it just doesn't seems like it runs like a 350 should and I've been thinking about it for awhile why this is and here is my theory/question. When you swap from a 305 to a 350 do you need to change the fuel injectors on the TBI or do something to the computer to get the proper amount/ratio of fuel into the now larger cylinders?:confused:
If it is starving for fuel it may be reason it runs poorly. Hopefully someon can shed some light on this.

I think the injectors are the same but the chip is wrong and needs to be reprogramed or replaced. check out thirdgen.org it's a camero site but there is a lot of good info on tbi there.

If I'm not mistaken, the throttle body is larger on a 350.:skull:

The throttle body is the same, I believe the injectors are different, though. The injectors are a bit pricey, but the dealer should have the chip for pretty cheap (my buddy paid around $30-35 for one for his 4.3 Vortec). Those 2 things should be the only difference.

Pete

So I need both the chip & the injectors! Bummer. Anyone know what the differences between the 305 & 350 injectors and chip are?

If you are gonna get a chip go ahead and get a "performance" chip like "Jet" or something. I would "upgrade" injectors too. I don't know this for certain but I have been told the "lobes" on a carbureated engine "CAM" are different compared to a injected engine. Was the 350 you swapped in a "injected" motor?

PS: Let me know if the cam lobe is different between the 2 engines....:beer: :beer:

To be honest I don't know how different the cams are but the engine itself used to be carbureated once upon a time. How sure are you that there is a difference between and "injected" cam and a "carb" cam? All we did was throw the 350 in there and kept the 305 intake manifold and TBI and added all the sensors that the 350 didn't have. All I know for sure is that it has been running lean.

swap the knock sensor!

the tbi injectors are different also