Here's how your VIN decodes.
(and going by the vin it's a 77, but maybe it was just built at the end of the model year or something)
It's a Cherokee 'S' Custom, which means 109" wheelbase.
GVW 6025#
Came with the 175hp 360 (AMC built)
Transmission is either T18 or T18a (the 'a' has a wicked low first, something like 6.2:1)
Tcase will be a D20
D44s front and rear (most came with either 2.72 or 3.31 gears)
Being that's it's a cusp year I can't say for certain but that list should be pretty accurate.
Other nice things are the factory 210 York compressor, that works beautifully for OBA setup. Mine doesn't have the 360 so can't give any hard advice of performance mods for it, other than there are TONS - shouldn't be any emmissions crap on it at all in 77.
There are a few options for suspension (I mention this since I have no idea what your build plans are for it - if any). Only a few companies make a 'kit' for them. They are BDS, Rusty's, and BJ's Offroad. Some Chevy 3/4ton springs can be mixed into the packs for a few inches lift. Can't remember off the top of my head if it's the 52" or 57" but tou can verify that with a tape measure. 5" or so can be acheived easily with a SOA up front and shackle flip in the rear. Stock you're looking at 31s with no lift unless you trim. 36s stuff easy with the SOA/Flip.
I've got a bit of a novel going here so will leave it at that for now. If there's anything more specific just say the word and I'll see what I can do.
www.rustysoffroad.com
www.bjsoffroad.com
www.hoyboyz.com
(in Lethbridge if you don't know then) Rob is the local BDS distributor, so can contact him
if want info on their springs - which are really nice but certainly don't come cheap.
Also, if you happened to see, Stacey did a quick build of a 77 on Trucks! TV. I have a copy of both episodes on the computer so can get you those as well if you like.
Good luck with the build.