i have a 1991 z28 with the 350 tpi, its been bored .30 over and im wondering if anyone can give my a ball park on how much, if any, power is gained. i plan on taking it to the dyno once i get some mods. but im just curious for now. thankssssssss

 

run 110 with octain boster

 

If all you did was bore it 30 over, then you gained about 5 cubic inches in displacement. Typically, that adds about 5 lbs in torque and maybe up to 5 HP (compared to a new, stock engine), but no more. However, if you rebuilt the engine it was probably because the old one was tired and not performing as good as new.

Did you do any other mods?

 

What do you have for other mods? The 89 & Later 350TPI responds to mods fairly well, although the TPI still falls flat on it's face at 4500RPMS.