Hey guys just want to say thanks again for all of the advice and support. Couldn't have done it without your help!
I finally finished swapping out my transmission and it was a success. It took a good 20 hours and quite a few cuts/bruises but it was totally worth it. I think i could do it all in under 10 hours after this experience, especially if i didn't have to do it on Jack stands!
It's a totally different car and with the z4 3.0 ssk and the vorshlag tranny mounts it feels like a racecar.
Anyways if anyone runs into any hiccups along the way I'd be happy to help. My only regret is that I didn't get to take enough pictures to do a writeup, which is a shame as there's not much info on just a straight tranny swap on any of the forums.
Also beware of the different transmission input shaft pilot diameters! The m10 engines and I think pre October 1990 m42 engines have a smaller pilot and require a smaller pilot bearing. Can't remember exactly where the split is but check realoem and make sure. I'm not sure what would happen if the bearing were larger than the shaft but I'm sure it can't be good!
Thanks again y'all!