How can I tell if an a/c compressor has a 5/8 or 3/4 suction port without taking the compressor off the engine?

First question. Do you have a vacuum pump and manifold gauges to recharge the system? Once you open the a/c system you will let air in. that air has to be vacuumed out before you can recharge it. If you do have the necessary equipment, then i would ask the parts store to see the new compressor and compare it to a photo of your old one. another option is to measure the fitting and ask to see both manifold hose types.

I don't have a vacuum pump or gauges. My ac ran out a long time ago. The reason I'm replacing this compressor is because the pulley is failing. The mechanic I spoke with said that if I can find a pulley and hub he can just replace those parts and keep the old compressor on but I'm having a really difficult time finding the hub. My father in law suggested that I just buy a whole re manufactured compressor but now I'm having trouble figuring out what size.

I've contacted Chevrolet and gave them my vin number in hopes they could find out for me but apparently they got rid of all their information for those vehicles that are 2000 and older. I contacted a chevy dealer and did the same thing but the only results were its either a 3/4 or a 5/8ths.

http://www.oreillyauto.com/site/c/search/A!s!C+Clutch/02631/C0328.oap ?model=Cavalier&vi=1358557&year=2000&make=Chevrolet I believe your mechanic is asking for this. it is a clutch,bearing,and pulley kit.

Did anyone ever find out? I need this answer =D