[sammyg2]

Yup, mine's an OEM york, the suction side is the lower port. The suction side of the compressor pulls from the evaporator in the front of the car through a larger diameter hose. The discharge side has a smaller hose and goes to the condensor on the engine lid. Don't get em mixed up, bad things can happen.
No sut-off switch on my compressor but I may add a high/low pressure shut off switch after I get my gauges.