I,ve got a 390 FE in a F-250 Highboy with 4.10 Gears and a granny 4spd. So needless to say it gets about 10MPG up hill down hill and at an idle....So I recently called up Richmond Gear for a five or six speed, mostly for the overdrive gear, and they claimed that thay didn't have anything that would work. It has a divorced transfer case so if i can get a 2wd transmission all I would need to do, would be to get a drive shaft made (and an adapter plate?). So any information would be like gold to me.