'79 F150 4x4. 400cid, 4 barrel carb. Short box with 38 gallon fuel tank. I'd like to know the pros and cons of converting to propane. What engine modifications are needed, what about fuel tank(s) that would fit behind the rear axle. Not really excited about a big tank in the box.

 

My cousin just did this to his truck. I saw it for the first time Saturday. The whole system cost him under $500, but that doesn't include the tanks. He uses two 85 lb. tanks (3 feet long and about 12" in diameter) from a forklift and they mount in the bed.

The biggest advantage to propane is that you can run it at extreme angles and not have to worry about carb problems (no floats).

There are several cons, but nothing major. Filling the tanks (as we found out Saturday) can't be done by just anyone. The forklift tanks have a different fitting than your gas grill tanks, so we had to go to a heating contractor to have 'em filled. You also get an average of 10% less power out of your engine with propane.

I'm not too sure about engine mods, but I know before he converted, it ran on high octane race fuel. LP is also high octane so he didn't have to modify his at all.

As for putting the tanks under the bed, I suppose it could be done. However, all the tanks I've seen are cylindrical so as you go up in size, they just get fatter. Anything bigger that the forklift tanks probably wouldn't fit. One tank lasted us about 3/4 of the day on the trails, then he had to physically change tanks. With them under the bed, this would be a little harder to do unless you had an access panel in the floor of the bed.

I know he did his homework on the conversion, so if you really want more info, I can probably get it out of him.

Kevin K.