318 poly wide block

Some other considerations, I'm not trying to make light, here:

What sort of help can you drum up, in the muscular variety?

Power tools? Or at least a GOOD selection of stuff like 1/2 drive sockets with a long breaker bar.......those transmission bolts are likely tight, and the crossmember bolts likely rusty

How about jacks, straps, hoist, etc? That transmission is HEAVY. At my age (69) I could not lift it from the ground with plenty of room to wrassle it, much less get it in and out of a confined area

Support the rear of the engine? The rear of the gearbox (transmission) is what holds the rear of the engine up. You will need some sort of jack/ blocking/ ratchet straps whatever it takes to put under and support the rear of the engine

Having no idea of your skill, friends, equipment at hand.......Even for a (admittedly elderly) guy like me this is a BIG job