Project just starting.

The truck is almost impossible to move even when it is out of gear, well at least we think its out of gear. It doesnt seem like the parking break is on and the brake lines are missing, so i wouldnt think they would be locked down. If you jack up the rear end and try to turn one wheel manually you can't get it to budge. Any ideas. Also, does anyone know what weight of oil to use in the rear end? It is a 1950 3600.

Thanks


1950 Chevy 3600