I believe the 1/2 ton GMC rear is a spicer/dana 44. If it will mount it should work, and there are many ratios available for ring/pinion, unlike the Chevy rearends. Someone please correct me if I'm wrong.
Jeff


"Do not walk behind me, for I may not lead. Do not walk ahead of me, for I may not follow. Do not walk beside me either. Just leave me alone, you're starting to freak me out."

1957 GMC 150