I have found a Chevy 10 bolt rear end with 3.73s at the junkyard. Its dirty but no grease. I took off the cover and everything looks clean, smells like used gear oil. The pinion gear end spins smoothly with either tire being spun. But if I apply pressure to the pinion gear end and spin the tire, it holds in place and the tires spin freely. Is this normal? Is there any other test I can do before I buy all the missing brake items for it?