This is some good info cause I've been wondering about this cause I'm wanting to do this myself. 13 gallons on a trip just plain sucks, would be nice to have a 20 gallon. What all rigs had the 20 gallon tank?
I did not know any trucks had a 20 gln tank, I was thinking I had a 18 gln tank on my hands. till I drove it to fill it up.
anyway I don't know how many or anything about what ones other than a 85 long bed "1 ton" that have a 20 gln tank.
butt nothing wrong with 18!