May I ask, in dogleg exhaust port style heads, are not the runner volumes
the same in the 304, 360, 390, & 401 Heads, just the valves are smaller
in the 304 heads, at least in 1970 anyway ?
I had thought that the heads were identical except for the valve sizes, so I started going through my AMC tech data, and found in the "AMC Power Book" by Martyn Schorr, several different places where the various contributors stated that the 304 heads had smaller ports and smaller valves. It would be worth CCing them to be sure, the crawler guys could use smaller ports and valves to some advantage.
Or are you saying the runner volume is less in the '69 & earlier rectangular exhaust port heads ?
The early heads are entirely different design and castings, I certainly would not expect that the ports are as large as the late heads, since the late heads are so much better. I, of course, have NO use for the old heads and long ago exiled them all to the dump. They too, may be an advantage to the crawler guys and I'm sure it would not be that hard to adapt them onto the late blocks, 290s having the small valves, would also be advantageous to the crawlers.
