440 Head and cam question

Depending on what you're doing, it may be a wash. The 906 exh port is better, the exh valve is bigger, and the intake flows a little better. It's going off an article I read somewhere else, but the 516s dont flow as well, mainly at lower lifts. There is less than 11% in that article difference between the two at max cfm, but the 906 flows 6% more by .300 lift. That's where the typical street cams make or break you. You'll be giving up an across the rpm band power loss with the compression drop, but that's not like 2 points..It's only about 1/2 a point. I guess if the cam is smaller, and a modern grind (like fast rate of lifts..) then you may notice a little gain. Mill the 906s a bit, and you'll see more like they said...