Despite my heavy dislike of the show "Trucks!," i would suggest you watch this weeks episode for some tips concerning gas to diesel swaps. i think they are doing a cummins swap, but some of the info could be helpful.
NOTE: They have also shown blatant displays of racism/predjucdiseness recently on this show. How sad. Both of the these hosts as well as the show itself have, in the past, disapointed me. But now more so than ever.
But yeah, go diesel. Diesel is cool and probably one of the answers to our "crisis" if there is one.