Could be too soft a shock, poor alignment/balance or just plain old **** poor tires. I NEVER had any luck with either Goodyear Wranglers nor BFG A/Ts and would get uneven wear and cupping from hell out of both of them.
Tire dealers originally blamed my truck at the time, but this is when I made my move to Mickey Thompson/Dick Cepek tires and on that particular truck, I never again had a tire issue with NO other changes made.

Once a tire is cupped, it's f*cked. If it's in the budget, replace them...


I'm glad you like the shocks, btw. I have to be careful about coming straight out and saying "the RS5000s are great, get them" because I did this once before and the pansy a$$ didn't like the firmer ride they gave and basically gave me a rash of sh*t on a forum like it was ALL MY FAULT he wasted money on them...

 

Lol. Sounds like he should have bought a Caddy then. The tires on there are Peerless Widetrack Baja, a Firestone knockoff I understand. When I bought the truck, the 2 fronts were new and the 2 back (same brand) were wore to the wear bars, so I just bought the other two to match. I've only seen these kind of tires once on a co workers vehicle and they seemed to be wearing nicely. Could very well be the tire though. Before I buy a new set I want to see if the last one cups or not. Sucks too, these tires still have 75% tread on them.