Ford has just introduced a compressed natural gas conversion package for the 3.7-liter V-6 version of the 2014 F-150. The package has hardened valves, valve seats, pistons and rings for the engine. After the conversion, the truck will be able to burn gasoline, compressed natural gas, and liquefied petroleum gas. It can only run on one fuel at a time. The package itself will be about $315, but the full conversion by a Ford Qualified Vehicle Modifier will be anywhere from $7500 to $9500. Ford claims that customers who convert their F-150s can break even 24-36 months, thanks to the low price of natural gas; compressed natural gas only costs roughly dollar in Oklahoma and $2.11 on average in the United States. For now, Ford is the only automaker to offer a natural gas package for its half-ton pickup truck, though other trucks can be converted to run on natural gas in the aftermarket world. Within the next year, Ford anticipates it will have 8 compressed natural gas mo...