I have a 1989 G20 Chevy van with a 5.7 The air compressor is making a lot of noise I'm afraid it's going to seize up on me. it does have R 134A in it. I was told when you change to 134 it could be under more pressure and cause the compressor to go bad so I was wondering should I put a newer type compressor in there if so where would I get it
I would get a new compressor. I would check RockAuto below or your local auto parts store (Advanced Auto Parts, AutoZone, etc.).
R134a does work under higher pressure so it puts additional strain on the compressor which could well be enough to put an old one over the edge. Any new compressor you buy today will be R134a compatible. Stop using your AC and replace the compressor ASAP before it seizes up. You can buy a new compressor just about anywhere that sells auto parts.