[lbpd719]

most likely an early "American" set..

The most collectible of that style was the "Shelby Cal-500", which was an actual magnesium wheel (100%), thus the name "Mags". American, Cragar, and several importers made them, however most were aluminum or some mixture of alunimum with magnesium.

Back side will tell you alot more about them though.. Cragars will be marked with a CM usually in the casting.. American's had the more dominant "3 hole" cap early on, moving to the captive cap with the "A". Cragars and Shelby's are commonly 4 hole caps. The correct Shelby caps will have a cobra on them and are a little more difficult to find.

Shelbys are also able to be spot by the way they are machined, and they were the only ones with a groove near the top of the bead on the rim.