72 cutlass it has all the parts. I just bought a compressor. A parts guy told me I need a poa expansion valve to convert from 12 to 134a. .. need info on the best way to get some cold air. And where to purchase whatever parts I need

 

This has been addressed here, and even more on V8Buick.com and AutoACForum.com - You would be wise to do some searching.

What you need is either

a.) to recharge with R12, as the system was designed, or

b.) to replace the receiver/dryer with an R134 compatible unit, replace the condenser with a crossflow type, instead of the original serpentine type, possibly replace the hoses (opinions vary, and you may do just fine with the old ones), flush the entire system to clear out the old oil, readjust your POA valve to work with R134, and refill with R134 at 80% of the amount specified for R12.

Easy.

- Eric

 

Does the existing sytem hold pressure and fully funstional other than the compressor not working? If you are lucky and this is true, I would consider finding some R12 as Eric mentioned.

If the system is in parts and/or has multiple leaks, think about dumping it and starting over with a Vintage Air (or other) aftermarket system. Not cheap but getting an old system restored and converted to R134 can be a slippery slope.