you can jack up the rear axle and count how many times your tires spin per driveshaft revolution
only the 2wds came in weird configurations other than 1/2 ton
I had a weird 2wd, that apparently didn't exist, is what everyone told me, but it did.... so..... basically, my 85 std cab, 6 ft bed (short), carbed 22r, laser block, had an 8" rear end, 3.07 gears, a w55 and was still a 5 lug 1/2 ton..... It also was an 85, but had a plastic tailgate handle, and an external bed rail
people were sure I did not have an 8" rear end, but I put the rear end from a friends 86 4runner with 4.10s in it and that was 4wd.... so......