My '77 240 doesn't have the rotolock valves on it. The York while a good compressor probably takes more HP to drive it. The WAY OVER-ENGINERRED compressor mounting bracket makes it a real pain in the butt to change even a water pump. the whole thing has to be pulled away just to get 2 or 3 bolts out to remove the pump. I had to change the exhaust manafold gasket at the head and YES the whole bracket had to be removed. If I was having issues with the R-4 Harrison compressor, I would spend the $$ and buy a NEW one. My opinion you would spend less that way then trying to convert it. Your A/C LINES also wouldn't work.

__________________
My Truck.. 2007 DODGE, 5.9 Cummins, 6spd stick, 4X4. My car..1977 240D, OTHER WHEELS...1955 VW Oval window bug, European Delivery (Holland) with a 1700cc, 2 barrel, Porsche drum brakes. 1939 WILLYS Pick-up. 1967 Triumph 200cc Tiger Cub. 1976 Honda 550F 4cyl Motor Cycle.