I know this is an old article, but I had some coffee time this evening, and put together a little chart based on the results of this article. The way they organized the article, makes it very difficult to compare what they really found. Thought it would make for interesting discussion, regarding cylinder head volume, and how much emphasis is placed on it.

I myself, find it pretty interesting, that a 360cc head, with over a full point less compression, only gave up 20ft lbs at 4000rpm, and 30ft lbs avg from 3500-6500 rpm. And that was a chitty procomp head, as cast vs a CNC ported head.

Its a no brainer, based on this test, just about any aftermarket head, kicks the stock GM heads azz. Mainly in the upper rpm. I think that has nothing to do with port volume , but simply a lack of airflow. The GM head faired pretty well in torque at 4000, but dies off in the upper rpm area. I see this alot with friends builds using those heads. They make good low end torque, just die in the upper rpm. Just had a buddy dyno a 496ci with 088 heads. Engine made just over 615ft lbs, but only 580ish hp. Flat tappet hydraulic. They just seem to run out of steam when its time to start building hp.

Any thoughts on this topic?

Velocity. The 088's lack it and it shows at the higher rpms.