[justcuz]

Your best bet would be to find a shortbed 4x4 frame and swap over. If you can't do that then look for a donor frame and just swap over the 4x4 stuff to your chassis. Most of the holes are pre-drilled and it is a lot of work, but if done carefully works out fine. I am doing this to my 1973 Suburban using parts from a 74 Blazer frame. I would recommend 2 improvements during the swap. Box plate or reinforce the factory engine crossmember. Add an aftermarket steering box brace. Also if your truck is a stick, (and your are swapping in an automatic) leave the bell housing crossmember in, it adds stiffness to the chassis. I will probably make mounts for mine that use the two lower auto trans mounting bolts and drop down to this crossmember. That way I do not have to install the rods that go from the engine mounts back to the bottom of the bell housing that tie everything together (which does not strengthen the frame, the crossmember does). Personally I prefer 3/4 ton axles, however if you stay half ton 6 lug, find a semi-float 14 bolt out of a square body and swap out the 8 lug axles and drums with 6 lug axles and drums. There are 3 width axles on the semi float, the widest is from an H2 Hummer I believe they may be 8 lug only. The other 2 are from light duty 2500 trucks 88 and up. The 4x4 axles are 1.5 inches longer than the 2wd axles. I think the 2wd axles are the same length as all the square body 8 lug axles. Measure to be sure. I think wms to wms on the 2wd SF is the same as all square body 8 lug SF. These have 35 spline axles and will last forever in the back of a 1/2 ton shortbed. They are rated as a 5000 lb axle. The front axles in the six lug are pretty much the same strength whether it is a GM 10 bolt or a Dana 44. They use the same outers from the knuckle out and I think some of the axles interchange. For eight lug stuff you have a choice of the 10 bolt, Dana 44 or a Dana 60. A Dana 60 is overkill unless you are gonna wheel it to death or plow with it.