A travel trailer will cause a LOT of HP needed vs a boat or equal smaller frontal area trailer. Me running down the road at 15K with my equipment trailer. about 70 sqft of frontal area, I need 105HP to go 60 on a level. Change that up to my old TT with 90 sqft, I need 135HP. With ET and my bobcat at 18000 lbs total, I need 115hp at 60. Now to blow you away some more, my Navistar at 26000 lbs and 70 sqft, also need 135HP. So that extra frontal area is equal to 11000 lbs of trailer weight, due to the wind drag!
TO make a LONG story short, the OP would be better power wise, gear wise etc with the new rig, as it has 50 or so more hp, torque, 6 forward gears starting with a 4.10 in first vs 3.08.
Also, at elevation, as noted in colorado at 8-10000', you are down in either case some 30% of sea level HP. Only way to fix or help this is more HP at sea level motor, ie a 6.0 or bigger higher HP motor, or a super/turbo charger, then you have sea level HP at 10,000 ft or there about, then you start to lose it as non inducted motors at 3% per 1000' elevation gain.
marty