Try an outfit called www.vintageair.com They make a bunch of retrofit systems for hot rods and such. Your only other avenue would be to find a COMPLETE donor car with A/C. But remember that everything out of a donor car is 30 years old. I had a 67 220D and it had an aftermarket add on air. Never used it because the darned thing was S-L-O-W enough without the extra drag of running a compressor.

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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.