My uncle has an early 80's chevy c30 2wd dually Crewcab, what rear axle is in this? He says it is a 10-bolt, i very much doubt this because it is full floating.

dana 70HD or GM 10.5"12 bolt how many bolts does it have on the cover? the Dana has 10 bolts and the 10.5 has 14. i believe the Dana also has the filler plug on the cover.