I have the tera grapplers by Nitto as well in the 285/70 R17 rated at 3750 @80psi. One thing I found out is that Toyo tires owns Nitto Tires and has joined some type of rim/ wheel association. This means that the tires that were once rated heavy for us srw guys are getting there ratings dropped to meet the factory rim specs. I noticed on the Toyo website that a lot of there tires are only at 3195@80 psi now wear they used to be much higher. This came out of my tire dealers mouth so I believe there is some truth to it.
Very few companys in the wheel business are making 3500+ rated wheels , and if you do find what you like , trying to find the right offset/ backspacing is even worse. Having not enough backspacing pushes the wheel out to far and puts undue strain on your wheel bearings.
Just my 2 cents worth.
Beefie