Some help with a 400

The 787 HP? Our ported Edelbrock RPM's. 580 HP? 906 or 452 heads, I cannot remember which ones we switched to.

Here is a little article from the HOT ROD network on the engine when it made 723 HP on Comp Cams dyno.

2009 Amsoil/Mopar Muscle Engine Challenge LaRoy Engines & ProMax Performance - Mopar Muscle Magazine

We took it home and made a cam change and it went 787 HP on the dyno at Performance Auto Machine in Idaho Falls.