i just parted out a 1996 dodge 2500 that had factory propane---computer reflashed with dodge stickers--dual fuel----found the truck was ordered by texas parks dept probably as some type of government mandate-------the propane parts went to a friend that has a twin engine 1975 ford truck---he has twin big blocks with blowers on them----the rear engine sits backwards in the bed and drives the front axle--the front engine drives the rear axle---he can run either the front engine or rear or both---the hot rod guys around here all perk up when duane drives the truck to coffee....