How much compressor oil do i put in the compressor GMC pickup?

If you're only replacing the compressor and you did't blow a hose or something, 3-4 ounces should do it. It is recommended to replace the receiver/drier and orifice tube when replacing the compressor. In which case you would add 1-2 ounces more plus the 3-4 ounces for the compressor.