Near impossible to do without welding, especially on the rear axles. Not enough room for five new lugs, at least if you want it to be strong/safe. Others will have differing opinions. Plus, now you have mongrel brake drums too. Better idea:
Get one of several available aftermarket disc brake kits for the front. I used the SSBC disc brake kit on the front. Used 8.75 Dr. Diff axles in rear end, with the 8.75 axle B-body SSBC disc brake kit. (You could also retain drum brakes in the rear with Dr. Diff rear drum brake kit) Certainly not the cheapest way to go, but might be easiest, IMHO.
