There are two heads with the old style chamber. The first has small ports the other is the H head with big ports. They used dome pistons. There were two that used flat pistons. One with big ports one with small ports. All 302s used the big port with the flatter chamber shape. The other was used on 270s and maybe 248s. The best comparison I have seen is in Patrick's catalog. It gives casting numbers and measurements. The big ports are good for racing and trucks. The small ports work well on the street. They can be improved.
I kept over heating generators withe the old headers. The carb is a 500cfm. Someday I'll get the twin Zeniths on it. You need a closer look at my trucks. They live outside all year. They have the kind of patina the new guys pay for.
