The shop in my hometown in Southeast Texas that only rebuilt rear axles swore by using non-synthetic 85-140 in rear axles


'66 c10 rust bucket, 350 nv4500 stock bellhousing, '85 c30 front suspension, h072 rear axle with 3/4 ton rear coil springs
'67 cj5 225 oddfire motor, time for disc brake conversion, offset rear dana 44, intermediate pedals and steering upgrade
'48 3804 frame and bed + '52 6400 cab and front clip + 4bt, need to put them together