I've run dually's for hundreds of thousands of miles on my Dodge with a Bigfoot 3000 10-11 camper over some very nasty roads including trips up & down the Alcan & Dalton with no issues. Mining roads (rough scree) in Utah & logging roads in the Northwest. In fact I've never talked or heard from anyone who actually had that happen to them. I'd much prefer having two extra tires carrying my weight than the best, highest weight rated single. If you're going to blow that rear single SOME place, it WILL be in the WORST place. I did pick up a screw once on an inner & the only way I even noticed the outer had a bigger bulge at the bottom ( it was carrying all the weight for a while ) Didn't even break out the compressor, plugged it & aired up next town. I'm running Toyo MT's on my ambulance. 255/85/16 with a 1/2" spacer, 34.7 " I believe. About as tall as I'd want to go without changing the gears. 4.56 now. a 37 figure 4.88 at least & any bigger you should go into the 5's. Sometimes "Looks Massive" & cool doesn't work quite that well in the real world (at least mine) Good luck with your build