Those being early (70) axles they'd have 10 spline shafts. The later (76+) have 30 spline like mini's but the pinions are UBER weak! That coupled with the c-clips and the unavailability of affordable aftermarker parts makes them a bad choice.
EDIT:
And you'd be suprised as to their weitght too. On my buddies 76 with a full cage, winch, 350 and th400 sitting on 36's he weighs 4200 lbs. Same as my truck.
