Goodyear Gaterback?

That's the same one my 96 Cobra Vortec takes. I went to Murrays and matched it when I shredded mine. I believe the same belt was out of an 82 Buick Century with a 3.0L V6.
 
It's hard to say. .6 to .484 isn't that big of a drop as far as a belt size. That slight difference might be made up in the tensioner.


BTW...I know you have a 2V, but do they make a forged steel belt tensioner? They do for the 4V, and I bought one...because they have less flex and are HD so they less a tendancy to be the culprit to throwing belts.