What's very telling is the ~20 to 25CFM OOTB difference from .400 through .600 is going to be worth roughly 40HP or more to a combination with enough cam and compression to take advantage of it, that's a VERY SUBSTANTIAL difference.
The Story Bryce Mulvey (yes I am aware of the horror Show) told was that Procomp sent their Eddy clones to DrJ's/Airwolf for testing and they suggesting some mods to the roof and the next batch would outflow the Eddies. Full disclosure, my 414 motor has the Airwolf SBM (using Steve Dulcich's 408" shortblock) heads from the magazine article.
