I did some research on the York!
I got a part# for the serpentine pulley/clutch. It ain't cheap $81.06 + ship from Ryder truck.
I myself am going to see if there is room to mount it in the position of the 5.8L smog pump, if so I'll go that rte. If not, I'm running a power inverter anyway. I'll run a 1/2 horse 120v motor mounted in the back on my tool/cargo box with a switch.
The smallest York puts out about 4 cfm at 750 RPM & it goes up SUBSTANTIALLY with rpm! Will fill a 2 gallon air tank in 34 seconds! Says the use of a hand throttle to increase rpm is nice when running air tools. The York can only withstand 6000 rpm. Not engine RPM, York rpm. The serpentine pulley is 5 7/8" diameter (if I remember right).
These I have do not have York tags on them for the model designation, only Motorcraft ones.