Hughes big mouth heads

If you look at the big mouth minimum cross section 2.57" should be good for peak hp at 6900 rpm with a 408, for a 408 to make 750 hp at 6900 rpms is 571 lbs-ft @ 6900 rpm which should be about 634 lbs-ft peak torque, 1.55 lbs-ft per cid.

1.55 lbs-ft ain't impossible but far from what most can achieve, I highly doubt that they built an actual 750 hp engine from them. In Hughes write up on them they call them 700 hp heads still need about 1.45 lbs-ft engine to get there which is still fairly high but more reasonable.

Eric measured a 2.78" minimum cross section don't know if he didn't subtract the corners, but his cross section say 7500 rpm peak which would be more doable but his flow look even worse for the big mouths chances for 700-750 hp.