Brakes: Nice way is up front, use 88+ 'V6' calipers (have fins on them), and ~1980-ish FJ40 (vented rotors). With 15" rims, you usually have to grind, they should clear 16" rims fine. Now take your front rotors and old calipers and put them on the rear, using some bolt-on brackets. This, with a dual diaphram booster and 1" master easily could lock my 38.5s, and they are all factory parts available at the store.
Haggar what do you have to grind to clear 15" rims? The calipers? Who sells the brackets for the rear disc? What did the booster & master cyl come from? I am thinking about pulling the 35's off my Bronco and putting them on my 85 4Runner and need to redo the brakes anyway.