Hi Bennutts, I was upgrading my tires last fall cause there was no way I was gonna slip and slide around with those stock Firestones. Anyway, I went with a set of 295/70/18 Nitto Ridge Grapplers. I had them on my last rig and they are good for Winter driving and clean out instantly after leaving the gravel. They could not get them to stop vibrating and had to order another set. Same problem... They told me that the Nittos needed to warm up first, but after a 45 minute drive they never stopped vibrating! (Even after road force balancing) Well, I had to come up with a replacement so I suggested to the dealer Toyos. He said that Nittos and Toyos are from the same manufacturer and that he can't sell Toyos since he deals Nittos.
After some research I came across the Cooper At3 XLTs in the 295/70/18 size and after they installed them my vibration was gone and my ride was also smoother like the Firestones. The Coopers are an "E" load tire rated at 4080#s. I believe they are a 2 ply sidewall, but they have that extra tread on the sidewall that I like for running over curves when I can't get the Heavy Duty around those tight corners!
They are good in the Winter and they do not clean out instantly like the Nittos. I believe they clean out faster than the Ko2s I've had in the past... I've towed a 12k 5th wheel with the stock tires last year and really did not notice excessive sway, even with wind. I have yet to try these Coopers with the 5th wheel, but I will do so now that it is camping season.