Here are pictures of the sectioning of the crossmember.
Section it 1 3/4". Don't go 2", or you will have pretty bad steering problems. Your steering linkage will hit the bolts that hold the lower arms in place. Also, you will have to cut a 1/4" out of the top of your arm on the DS towards the radiator for a nut that hangs of the frame. Forget what that is part of. Also, you will have to move your steering linkage to the BOTTOM part of the spindle steering arm. How you do this is up to you. The easiest way, and the way my buddy is doing it, is drill the taper out to 3/4" (about the biggest part of the taper) and put heim joints on the ends of the steering linage. This will eliminate all of the problems up to 20s. 22s and you will need to notch some of the frame for the steering. You'll also have to angle your upper balljoint down, and cut out a stock suspension limiter. Thats about all it took to lay my buddys out on 20s. This was, however on an 80s style truck. Everything is very very similar up front, but there are little differences. So, hopefully this helps in yoru decision.
Also, on the body mount thing, I talked ot a guy at a show, with this truck.he said he put 1" tall rubber mounts under the cab.