1978 Oldsmobile Delta 88 Looking for a posi-traction rear e

Did the 1978 Old Delta 88 Royale come with a Posi-traction option? If not could another year from 75-85 or later olds metric four-link v8 posi-traction rear end work on my vehicle from a different GM model?

If I had some options, then I would call around to juck yards for the various model and year rear axles until I find a complete axle that I could buy and stick under the car.

Thanks,
Brian