What I gather, is, they are Dart 360's, that were ported by Steve Shmidt. Meaning, they are likely MUCH larger than 360. Likely 380ish cc+? Dart 360's with what I would consider fairly basic porting, meaning, not moving anything, just grinding metal out, with a larger intake, say 2.350, will make easily over 1000 hp.
As far as compression, due to the altitude, as much as possible. 15:1+, which, is fairly easy to achieve in a 632. The one thing I wouldn't do, is use a mega huge dome to just achieve a number. I would mill the heads and use a moderate dome, vs a huge dome, and more chamber. The engine will make more power at say 15:1 than to 16:1 with the huge dome. There is also a point of diminishing returns on cr.
Frank