Why would you recommend CW for tires? In Montana, he's in Schwab country and can get Toyos for much better prices than most other brands.
The RV we sold last December was also an '02 on the F53 chassis. Performance was excellent, particularly compared to our previous '85 Class C with a carburetor-equipped 460 V8. We didn't cross the Rockies in it, but did go over 5200 ft high Washington Pass on SR-20 a few times.
We didn't tow with it, and occupancy was two adults and two Labradors. We were well within the 22,000# max weight limit.