The trans is on the engine. Flush, with 4 bolts in. .....took me 3 hours and 15 minutes. I don't think that's bad for a first time....old fart job.
It took many angle and height adjustments to get it against the dowels, then I had to put my bottle jack under a front corner of the bell housing to rotate it a little. It moved freely so I wasn't worried about it. I had a couple pieces of paint stick between the bottle jack and bell housing. By then the angle was pretty close and I put the two bottom bolts in enough to hold well, lowered it and put the two second from the top bolts it and starting tightening them.....in order, round the clock to keep them even.
It wasn't bad. Time consuming, I took 6-8 short breaks. I'd call it damn fussy, but all and all, it went well.
Four bolts worth. Lots left to do.