Better Gas Milage and Shift Lock on e-350 based RV?

I traded an 1999 f350 7.3 (4r100) with a camper for the e450 ford v10
class c
the diesel would pull Mont Eagle in Tennessee without down shifting

but..the 7.3 gets it's max torque at 1600 rpm vs. the v10 at 3500 or so rpm..

I agree with previous comment...lugging is no good for engine or tranny.

it has taken me a little getting use to with the shift patterns of the v10 vs the 7.3 ...and the fuel mileage 13.5 vs 8.5

but everything has its down side.

but I do enjoy the v 10 and it does have a good reputation.