Wouldn't slot of this depend on the class you intend to run the engine in? This is all theoretical thinking but a BB is going to be most competitive if the cubic inch is held below 360 cubic inches with the cylinder heads that are currently available. Obviously, I'm not an engine builder but my thought is you can size the bore such that the cylinder head ports can have proper air speeds and competitive flow for that particular bore size. That would mean custom crank and block, and long rods to make that work. As Al stated, there are more competitive and researched combos available. I think it would be interesting to see somebody run one in C/D, E-F/A, and a few of the wedge only super mod categories. I don't know if there is a Mopar part numbered head good enough to be run in any of the econo wedge head classes. Al, do you think the predator head would be more competitive at a smaller cubic inch(360-380ci)? Hopefully my thought process isn't too uneducated, just thinking out loud.
There main thing going against it would be the block deck height. Weight of reciprocating parts, the valve train design etc. A 99/06 Hemi has a 9.0" deck height. Most P5 stuff is down around 8.3" vs a 9.98" deck height for a B series block.
For the most part, the heads and induction system aren't particularly efficient, as you've mentioned, the Predator head is the only thing that would be close. The whole deal would be heavier than anything in it's class and make less power.
