i have a titled 1974 C10 Stepside. Lots of different years of parts on it so I say titled. The engine is a 350 with no port for a mechanical fuel pump so maybe an 80s block? Anyway it is using R134 gas for cooling. The compressor is stock. I think the guy who replaced it for me years back said an A4. Anyway it is cooling great but is annoyingly noisy. Has been noisy since it's installation, but I am becoming more annoyed by the noise. Is there an after market compressor that is known for quiet operation? Any way to quiet down the compressor? Any thoughts appreciated. Thanks in advance for your response.