So it has a Thermoquad, NP435, Dana 20, 760X series U-joints, Delco-Moraine master cylinder (2 bolt mount, left side lines), and Saginaw steering... I'll assume a transfer case mounted brake which would be typical of OHC230 powered Jeeps and consistent with every FJ-40 made. So, what do you need?
Let's see, LOL
The engine was built with a TQ, but the one on it gave some trouble, and this variously had everything from a Q jet to a Holley SB to an AFB
I don't speak "Spicer," but it used 369 Precision joints at the transfer, and factory LC joints at the axles
Don't remember the details on the master anymore
Saginaw box out of a Chev Impala, I think
Now if the TC had a driveline emergency brake, and I think not, it got removed. The Wagoneer was a Jeep 327 I actually !!!!OMFG!!! never had an emergency brake after the swap, except for both a Line Loc and a (got back from Google) Mico Lever Lock lever operated valve which acts same as a Line Loc
During the large amount of time that I had that thing in runnable shape, I was myself a parts guy, so I didn't need to worry too much about parts.
Damn thing was about half dangerous. With Desert Dogs or BF Goodrich All Terrains, 70 mph was about 3K as I recall.
But yaknow that's the thing -- nowadays if you go in with something like this, these guys simply don't comprehend. Part if it is that they aren't mechanics, part is they don't care, part is the computer crap they use is a mess, and part is that there simply does not seem to be in existance the kind of numerical/ pictorial / and cross references that we used to have.
We used to have Bendix, Wagner, and Raybestos master catalogs. Not only could you look up something like a master cylinder kit from a casting number, but it gave you part numbers for every piece IN the cylinder---the piston, the cups, the etc etc.
We used to have TONS of books and cross references that amaze me yet today. Some of this is because we hoarded old catalogs.
And of course in many cases the product lines don't put this info out, nor make those parts available.
I recently went through FOUR NAPA brush sets for the "squareback" alternators. At least two had DIFFERENT parts in them than the other two, all four same part no. I finally was able to make ONE good brush set out of two or three brush sets, (which had been sealed in plastic) and finally just turned the rest in as "defective--boxed wrong."