The kits can be had in a multi-fuel set-up. I would use propane if I had to
take the gen to another location, but with NG plumbed right to the house, it
is a no brainer. Propane is a bit more expensive to run I think, but not as
high as gasolene.
In hunting it down, i spotted a guy who sells conversions for autos.

http://www.hendrixsystems.com/index.htm

C. Smith



I may have inadvertently mislead the readers. This gentleman claims he does
conversions for anything, but I also found out in the research process that
each auto conversion must get an EPA certification, (much like an STC) to be
road legal, and that process costs upwards of $50K.
Remarkable how our government says they want to help us innovate and
conserve, and work for oil independence. But every time you try to do it
they have a regulation that stops you flat. Funny, they let these bio
diesel/biofuel TV hacks burn whatever they want(god knows what comes out of
those tail pipes, and by the looks of most of those cooks, I'm sure they
haven't paid for any lab work), but you can't burn clean natural gas.....
Do I shoot myself now, or wait for civilizations' collapse later on????
C. Smith