hey everybody. I'm new here so I hope I'm posting in the right spot. anyways, I have a 1965 buick 300 with iron heads, Ive been told that I cant use an aluminum intake with iron heads is this true? do I have to get aluminum heads? or can I use the iron ones I have? thankyou.
The ports on the aluminum heads and intake are 1/4" smaller in both directions. It may bolt-up and work, not sure if there's enough gasket surface area to make both happy and not sure if there's enough material to port match them. When I buy a head gasket set for a 300 it comes with 2 different sets of intake manifold gaskets. You can replace both the heads and manifold but, in addition to the ports being smaller, both intake and exhaust valves are 1/8" smaller. That may give you better bottom end torque and fuel economy but it will hurt your top end.
Yes some people have made the alum intake fit with the iron heads, it can be done... Take the old intake off, put the intake gaskets on the heads and then on the intake and you will see the mis-match.
You might want to consider buying an iron intake and selling the aluminum one, as you could probably make money doing it and gain performance in the bargain. There is a definite market at BritisV8.org and mgexp.com Those are popular in the engine conversion market, as are the aluminum 300 heads. Jim
