Head swap
 

I currently have a 71 Pontiac motor out of a Grand Prix with 96cc heads, I have a 69 GTO motor with 72cc heads. I was wondering if I put the 72cc heads on the motor currently in the car will this make a big difference or is it not worth it. PS they are not ram air heads. Thanks in advance

Depending on the rest of the package(cam, intake, exhaust)you may see a little gain assuming your 69 heads have 2.11/1.77 valves. May end up pinging as well. I know my 400's with 72cc heads will rattle even at my 4500 foot elevation. Going to be worse at sea level.

Swapping stock heads for stock heads you'll see a slight increase in HP due to the bump in compression. You'll also see a need for higher octane fuel, likely higher than you can get at the local station. If you think gas is expensive, start mixing in $8+ race gas and it gets real old fast. I don't think swap is a worthwhile proposition.