My air con piston type compressor has been going for years and I usually charge the air tank everytime I use the vehicle.
I also have a small dip stick in the side of the compressor and top up the oil every engine oil change.
My compressor uses the original 101s 24volt altenator drive belt and pulley set up...........I don't know the gear ratio compared to the engine, most likely slightly higher/faster.
I find at 2000rpm engine is more than enough air for anything you may need, but heat will build up quickly as the compressor has no cooling fins etc.
If pumping tyres .......usually for more than one vehicle, a fast idle speed is enough to maintain pressure in the tank and heat built up is reduced and therefore I will have along lasting compressor and little risk of melting the air supply hose to the tank.
My Nippon Denso piston compressor is much smaller than a York
The limit to pumping tyres at a fast idle is the restriction of the tyre valve.
I can spin the whole thing at 4000rpm engine speed, but there is no need to.
I can spray paint at 2000rpm engine speed and run a rattle gun for a short time.
The 101s air system has been used from time to time for on site stripping of old vehicles for spares or replacing the garage compressor at home if a friend has borrowed it.
Its biggest job has been charging the air brake system of a truck which lost its air.................it took a while at 1500rpm , but did it in about 10 mins.
Expect good things from your set up Gav.
You will find any electric compressor will not cut the mustard to a engine driven York on the tracks pumping tyres and of cause working air horns.

