A search on this will give you loads of info. The short version: it is not a direct bolt in. Improper disassembly can cause bearings to fall into the transmission housing. You also will need to purchase shims to ensure proper shaft endplay. I had the same questions, and ended up using my old retainer. One of these days Ill drop the trans again and change it.
Same here. My engine was going in that day and I was already about a year and $2000 over budget for the whole thing, so shims were out and I wasnt waiting any longer.
yep, and if you dont tilt the trans the correct way, you will dump needle bearings all over. there are a couple of real good threads on this (Rick 91GT answered, and so did someone else [sorry i forgot who] - both had real good info).