906 heads and 740+ NA horsepower?
I've been pooh-poohed enough on the claimed flows.
I'll just say they do make the 748 HP on the 91 octane pump gas, 11.9:1, 500" engine.
And 694 HP on the 91 octane pump gas, 9.7:1 compression, 451" engine.
There are enough guesses out there on how many horsepower you can get per cfm.