Rear axle question

[Coronet 14]

I was looking at the rearend on my 72 Coronet and with the rear wheels off the ground the rear wheels spin.
The vehicle is in park and the driveshaft doesn't turn. Vehicle doesn't move on the ground. Usually in a vehicle you can't spin the rear wheels even off the ground when in park. Is there something wrong here?

 

[Meep-Meep]

Nope. You are giving the spider gears a workout. If you had a sure grip then you shouldn't have movement.

 

[terzmo]

wheels don't turn in park, that's why your car stays put when turned off and placed in "park"....

 

[67 coronet]

i figure they are turning in opposite directions of rotation.that would indicate an open rear diff.

 

[5.7 hemi]

Yep, open diff.

 

[Cranky]

Or a worn out SureGrip....

 

[Coronet 14]

I know that if you smoke the tores The right tire will spin for a bit then the left one will leave tire marks. Will the vin tell me if it's got limited slip.