Note: This discussion does not include Magnum heads:

308 chambers as found on an engine will run 68 - 72cc, maybe even more. They will look the same as any other 360 head.

Only 273s and 318s came with closed chamber heads. The majority of 318 heads are open chamber.

The 302s are not for serious power. Sure, Dulcich got mega power out of them, but what you may not know about his "super ported" 302s is that shortly after he began to use them, one of the ports developed a crack and now he is not recommending them for performance, at least that's what I took from a private post.

The 308s had such a good exhaust port that the stock camshaft for the 360s that used them had more intake duration than exhaust. It's usually the other way around.

There is no way to get squish in a 360 chamber without either using step head (quench dome) pistons or welding up the head to create a squish pad.

There is no Mopar LA closed chamber head that is even close to 70cc.

R.