I put this same set up on mine without blocks or anything, zero issues. Upgrading to 16" rims was a game changer
As for weight, mine loaded was near 17k, full fuel, full water, Funco Gen 4, two full sized quads (they were stood up) and an LT80 in the Kitchen. And it was full of everything for a 5 day trip for a family of 5. Not much else could get in it.