89 9c1 posi?

I have a 1989 chevy caprice 350.... old police car So i was changing a tire so i had the back in lifted up. so i decided to put the car in drive reverse etc and the wheel on the driverside spinned freely, the passenger side spinned slow than spinned in clicks like it was being caught up on something ...Is that normal?

The clicking sound you heard was likely the adjuster on that brake assembly that was turning backward. Look at the SPID label in the trunk - if it has 'G80' on it, you have limited slip (posi), if not, you don't.