Sorry for the late reply, been busy with other things.
Basically what I did was bolt the transmission up to the engine, then jack the back of the transmission up far enough to bolt the crossmember in place. I originally tacked the mount on kind of at the bottom. Bottom of mount even with the bottom of the crossmember. When I test fit, and had the trans as high as I could, but with some clearance left between the trans and the tunnel, and I had the rubber mount in, I could see that I should have welded it a little higher. Left the transmission jacked up where I wanted it, I took the crossmember off, and cut off my tack welds. I moved the mount up just a bit, probably between 1/4" and 3/8", and welded it in place for good. I didn't want to go too high, cause then if I had problems with clearance I'd have to cut the welds out again. I purposely left it a bit low, and if I needed to bump it up a little on final install, I could just throw a couple of washers in between the crossmember mount and the rubber mount. Which I did in the end. Just tried to get it looking level, and the tail end looking the same distance from the too of the tunnel as the old 904 was.
I didn't use gauge to check drive line angles or anything, and it all runs smooth. But I do plan on getting one and checking to see where I'm at. Just didn't have one at the time.
I hope that helps some.
