The easiest way to tell if it is r-12 or r-134a is to go out and look at the a/c lines. If the low side connector is threaded, then it is r-12. If the low side connector is a quick disconnect, then it is r-134a. If it is r-12, then you must 'techincally' get it vacuumed out by a shop that will reclaim it, then get you one of the retrofit kits that will adapt it to r-134a. It would also be best to replace the drier before you retrofit it, but most people don't and never see a problem, at least right away.

Richard <img src="/forums/images/graemlins/patriot.gif" alt="" />