1991 Isuzu Rodeo "looking used ac compressor 91" Questions

...AC Compressor and just put a smaller belt on my car so that way the noice would go away. Is it possible to do that and if so what size belt can i use since the original belt for these cars are very ...

...ac compressor on my 95 chevy k1500 pickup went out. the sytem on it uses r134a. I pulled one out of a 91 pickup which used r12. Both units look identical. My question is: are they interchangeable? ...