i have a 77280z 4 speed. i need to know what year models i can get a bolt in, r-200 3.7LSD, 3.9, or 4.11 from. also, will any of the 5speed manuals just bolt in (with the crossmember of course) or do i need specific model years? i had read that on some cars, you have to cut the shifter opening, but the 5 speed was offered stock with my year model, but alas, i only have the 4 speed. i looked at some diffs at the local boneyard, but the mounting all looked different. like no mount on the bottom, all on the top rear. i'm confused now.