Rear end questions?

[lotsagas4u]

Hello, was messing with 31 pickup this morning, have rear end on jack stands. Was checking adjustments on brakes, trans in neutral, while turning the right wheel, I noticed the left wheel was not turning. I went to left side and turned it, the right wheel was moving. Brakes are fully backed off on each side. It has a 3:78 gear set in it, it will only run about 40, and that's pushing it. Does this sound correct? Engine is timed proper, and was rebuilt last year. When trans in gear, both wheels turn, opposite each other. Thanks