What wheels are these?

[AUS57SAF]

I'm not very familiar with lots of American GM stuff so I'm wondering if some-one can give me a clue on this.
The '57 Ponty I bought came to me with these wheels on it. They are 15" x 8" steels and carry a date-stamp 1984.
Does anybody recognise them and could tell me what car they would have originally belonged to?
Thanks.

[92conv]

Those are GM truck Rally Wheels, as you noted by the date stamp vintage 80's....If I remember correctly these wheels were available into the early 90's on select GM trucks.

[AUS57SAF]

Those are GM truck Rally Wheels, as you noted by the date stamp vintage 80's....If I remember correctly these wheels were available into the early 90's on select GM trucks.

Thanks very much for that useful information, greatly appreciated!