Thanks for all your help guys, but I have another question. Should I run a spread-bore or square-bore aftermarket intake manifold. Is bad to mix a spread-bore intake with a square-bore carb or vice-a-versa. Of the above choices which would give me the best economy and performance? Also does anybody know if shory hot rod headers will fit a 67 Chevy C-10, or should I get long dump headers instead. It does sit a little lower than normal so I am afraid that the headers might be to close to the ground if they are the long dump kind. Thanks Bobby.