There is a difference in a tow limit and a pulling limit dependent upon the ditch rating. Hitches rate their limit for trailer towing which has a tongue weight. If the hitch has 350 tongue weight it has a tow weight of 3,500 pounds for a trailer. That is not addressing a 4 down towing, i.e. wagon type of vehicle which bears it own weight.
Also his Motorhome build may be built with too little CCC therefore maxed out and overweight when loaded for travel.
I was addressing the capability of the '97 Ford 460 CI engine and E40D transmission to pull the 4,900 pound wagon type vehicle according to my experience, with a properly rated hitch and auxiliary braking system properly adjusted for the specific vehicle being towed.
If his MH is overbuilt for his chassis and his tow combination then he has a problem. Not all '97 35' MH had the same chassis and same weight of house built upon it. Not all taters are alike. :)