H.P. & Flow Improvement?


Active Member
Aug 20, 2001
i just recently purchased a set of heads that appear to be stock with the exception of larger stainless valves and upgraded springs. My question is if I port match the exhaust side of the heads with the fel pro 1400 gasket how much extra flow and horse power increase can I expect.
There isn't much HP to be gained gasket matching a set of buick heads. Especially if the manifolds aren't opened up, too. Even then its on the order of a couple % of flow increase.

If the heads have had a 3 Angle valve job, that's about a 7% increase in flow. Larger intake valves are worth 3%.

Your biggest bang for your buck is to bowl port and clean up the short side radii and the intake pushrod pinch. 10%+ and fairly easy.

If you get daring you can smooth and open the pocket and reduce the valve guide supports and open the ports. Another 10%+ but required more skill.