Tranny: NO, it won't bolt up to anything but an Isuzu 4 cyl. TH350 or 700R4 is easiest- and most popular.
Rear end: YES, it's about the same strength as the GM 7.5" 10-bolt that's in your donor Jimmy, then fab the drivshaft to match the tranny on one end and the rear end on the other.
'78 Chevy LUV,1.9,4sp,headers,31's,SAS Dana 30,Dana 20,SOA rear w/Aussie Locker, body ROUGH, bought new 12/4/78. A pre-P'up?
'87 Trooper,2.3,5sp,headers,31's,ball joint flip & spacer,Aussie Locker rear,Superwinch hubs,brush guard w/5.5K winch.