I have been looking at the benefits of running CNG (Compressed Natural Gas) or propane in my truck. The closest dealer i have found that can install a kit is in Austin but the problem is you have to use his computer and timing. Have you thought about putting a kit together and putting it on these trucks? The parts are not the expensive part that the guy sells it is his labor and tuning.

Propane has an octane rating of 110-120.
Natural gas has never cost more then gasoline.

If you were able to put a kit together i would be all over this.