Okay i was thinking about getting some help from my high school teacher to port and polish my heads and manifold of my 305 tbi.I was wondering if anybody here has done it and if so or not how much horsepower and torque would i gain.

THanks

 

I'm really interested in the porting/polishing of the intake also. I've got a performer tbi that I'm going to bore to 2 inches and would really like to get as much as possible from this manifold.
Maybey the carb guys could help since they use basically the same type intakes?

Later, Mike

 

I would find a pair of 416s to port and polish head wise; as for the intake, I say just go aftermarket. You are going to want to go with a bigger cam with those mods IMO though.

 

A good port and polish job can gain ya 20 hp. Don't polish the intake though, or the intake side of the heads. It'll cause the fuel to pool up on the walls. They are supposed to have alittle texture to them, but you can port them and gasket match them which will help out alot. Then polish the exhaust side and the combustion chamber.