So i'm currently building a 350 tpi to remove the baby 305 from the car. But i was curious if i was going to need a different computer or what was needed to get the engine to run right?

 

You won't need a new computer, but you will need to give it new instructions.

Most of the TPI hardware was the same between 305's and 350's. Harness, sensors (except knock sensor, and even it may be the same), base, runners, plenum, TB, exhaust (dual cat, anyway, in '91) - all the same.

Do you have dual cats? If not, figure on changing out the complete exhaust because the '91 single cat system was too small even for a 305.

 

I just got my exhaust done. True duals 3 in" all the way to the back with the 80 series flowmaster. deleted the cat. converter. Didn't know what to really do. Just a simple exhaust for mean while.