Before I went thru our old and used Majestic(gas)and Class C, I called an old friend (that is not retired yet) from a large trucking company and in charge of fleet maint of many, many units. Told him what I was up to and doing and didn't want to break down over a $10.00 part somewhere. Nothing but praise for gates belts, but he said not to by the strongest heavy duty one out there. He said premature failures does happen sometimes(with all belts)and the super strong heavy duty belts are so strong they don't "break clean" and sometimes get caught on different pully's or even scrape up or damage the front seal(somehow). Or when the mechanics put on the new belt they sometimes don't always check for old belt fibers or pieces that might have got caught in different places and those pieces could take out other parts as if they are rubbing againist other moving parts. He recommend "green stripe fleet guard".
And for coolant hoses he couldn't say enough good things about "green stripe 2" hoses. I looked them up and here is info on them from a fleet management point of view. Of course it is from Gates, so they aren't going to say anything bad about them.
http://www.gates.com/file_display_common.cfm?thispath=Gates%2Fdocuments%5Fmodule&file=Gates%20Fleet%... Just for good measure on ours, I also replaced belt tensioner and idler pulley and water pump. But that is on a small gas motor. Don't know what the expected service life is on hi-torque low rpm stuff is.
OK thought I'd pass along info I got from a fleet manager that I've known for many years. (Always carry extra filters, belts and credit card):B
2003 Majestic 23P... Northwest travel machine
2013 Arctic Fox 25W... Wife "doll house" for longer snowbird trips
2001 "The Mighty Dodge"... tow vehicle for "doll house"