Well, 31" BFG allterrains dont rub on my 89. Does the clunk happen in 2wd or just when in 4wd? IT its 2wd, it's probably the rear driveshaft u joints. As for the grinding, I'm sort of stumped <_<
Yeah let us know what it is if you find out. The fact that it only happens when turning hard in one direction confuses me. Maybe have someone drive the truck slowly with the wheel turned all the way while you stand, or walk next to it and listen where the noise is coming from