Farm tractor manufacturers built propane fueled tractors in the 50s and 60s that I know of. My grandpa ran his 1962 Ford C-600 COE truck on propane for a few years, eventually converting it back to gasoline. I know nothing of the details. I would guess that most propane fueled vehicles were aftermarket conversions done by custom shops and propane retailers. In the gallery is a 65 or 66 Chevy pickup with a dual-fuel system. You'll have to look for it. I don't think that person is active on these forums.
