How can you tell if a 1994 Pontiac Grand Am uses R12 or R134a freon?

There should be a sticker under the hood indicating whether it uses R12 or R134A. Unfortunatley a lot dont. The only way to tell is by the high and low side fittings. R12 fittings are bothe the same size. R134A has two different size fittings where one is larger than the other, ussually the high side fitting is larger than the low side.