I don't think anyone has attempted it. Any of the larger cube XR2 or Ernie Elliot block based P7 deals I have seen have been power adder combinations. I am in Australia, so I wouldn't see any where near the cars you guys would.

The Ritter blocks were designed primarily for the P7 head, the wedge head option was made to work with the casting. Either way, they come in 9.6" or decked down to 9.2"

As has been mentioned, Slawko and CFE have programs for the P7 head, where they shift the intake valve etc. I think any decent shop with experience in SB2.2 heads would be able to tackle a set of P7s. They won't out perform a P5 head.

A W8 engine can make over 1000 with a single 4 barrel intake, the P7 is a better head IMO