Magnum RHS Heads horsepower gain??

If you already have magnum heads and you're sticking with the Crosswind I doubt you'll see anywhere near 40hp. The intake is already a limiter. I'll add - Not seeing the head tests, IMO if the RPMs were down 50hp to the RHS, there were issues with either the condition of the RPMs when first bolted on (they were'nt corrected by a competant shop) or the combo wasn't designed right and the RPMs were the wrong head to start with.