Originally Posted by 77pontolds
Hello again. I didn't ask him how much he wanted for the heads, but I could probably buy them for4 not much. I dont think I can use them because they won't accept my A.C. .They are rusty from sitting outside in the shed, but WOW! they have big valves (they almost touch) screw-in studs, guide plates, and round ports (?). The other ones have larger c.c., and the right mounts, but are probably the same as I have on the '71 block.
When you hear production Pontiac heads called 'round port' or 'D-port', it's the exhaust port that is being referred to. The intake ports are all shaped pretty much similar.
You might want to look at them a little closer if the exhaust ports are really round. Double check the casting number. A photo would help. Be sure the ports weren't modified by grinding.
The images below shows Ram Air (RA) V top (you will prolly never see a set of these in the wild); RA IV (round port) center (one of the best production Pontiac heads); and the D-port, bottom (by far the most common design).