Yeah great start, I think Reb pretty much covered it, I would say that the newer 45 airsal have always been good for me, the 47 (or maybe it was parma?) was the one that back in the day was really wackadoo.
I've always been able to get them to line up pretty good with just a thick base gasket, the heads pretty much all suck for moby and keeping them cool is always a challenge, so don't be afraid to leave it spaced up a little bit on top, it will hurt the bottom end compared to a properly setup squish, but you can tune the variator to make up for it