Trouble getting a slant six in the car

I've probably changed engine trans combo's a hundred times in my life. Up until I was in my 50's I always used a set of tri-pods with a block and tackle my Pap and uncles used for semi work. A screw driver in the right chain link was all I ever needed to set the angle , get it wrong? move it to another link. This isn't rocket science it's a pretty easy procedure ESPECIALLY when you take advice from someone with more experience trying to help you .TRUST ME (and others) bolting everything together out on the ground and then installing as an assembly is the way to go.
Alright I’ll give it a shot. Don’t suppose I have anything to lose at this point. Someone else on here has me wondering if I’m going to have issues getting my 77 motor paired to my 74 trans. Is this a problem or do I need to put the other trans (the one that came with the motor) in there?