F250 460 not strong enough/Truck suggestions

[Arabnracer@aol.com]

Hi all you horse haulers------------have an 85 F250 4wd AT with an 8' s/c
camper and 3 horse stock trailer------am only able to do about 40 up the
passes at 6 mpg-am looking to trade the truck in for another used truck-
probably have to get a smelly, noisy diesel but wanted to ask the
professionals first as to what they like
Would like to be able to do 50 up the passes at hopefully 15mpg [dreamin huh?]
anyway please email me privately so as not to clutter up the list
arabnracer@aol.com
april
thanks