if i had things that far apart, id at least have the trans gone through. The torque converter in any stock auto regardless of the year is not well matched to the Cummins torque curve. Plus the stock trans in the motorhome is a non overdrive unit, which will, just like the pickups, will leave the cummins at a higher than happy rpm.
The ideal setup would be a pre 91.5 NON intrcooled engine, an A518 overdrive automatic with a good aftermarket torque converter and 4:10 or 3:55 rear end gears.
2014 CCLB 4x4 Tradesman. 5th wheel prep, upfitter switches, LSD, tow mirrors flipped, just like god intended
other rides: 1977 FLH. 1969 Diamond Reo C101