Here at Scoutparts.com and Travelallparts.com, we have and use a propane powered 1974 dump truck. It is the handiest thing that you can imagine. I have been so impressed with the advanced design. Although it is over a 1 ton truck, it drives like a big car. This particular truck is powered by a 345 engine and propane. Operating the propane has been a real learning experience (and the biggest reason that I bought it). I really wanted to know more about alternative fuels as it relates to IH trucks and Scouts. It has about 25 percent less horse power but it runs and starts like new. The propane combustion has only water and CO2 as its byproducts. As clean as it gets. With no hydrocarbon in the combustion the oil never turns black. This engine that will last for hundreds more miles.