I just did the 17.5 H tire upgrade. Certainly not cheap but after doing the IS and Disc brake upgrade, it was obvious that I was getting close to the weight limit on my G 614 tires. Mor/ryde weighed my rig at each tire and that was the deciding factor, I purchased from trailertiresandwheels.com and went with the Goodyear G114 H tires and new aluminum rims.
Tim and Paula
2015 RW 39MB - Mor/ryde 8K IS with Kodiak Disc brakes. Goodyear G114s on 17.5 Rims. 420 watts Solar on roof, 440 amps of AGM batteries, 2000 watt Magnum inverter wired to sub panel.
2016 Ford F-350 DRW - B&W 20k OEM Companion hitch, Firestone Airbags