I've been getting vibrations and Death Wobbles from time to time. It's a 91 Burb, D60 front, no lift, 33" BFGs, Hydroboost, EGR brake pads, most of the D60 and all of the brake system is new. I came home from vacation this weekend and was on a steep down grade highway. I noticed as I used the brakes more, the vibration and wobbles got worse. When I got back on flat highway and wasn't on the brakes as much, the vibrations went away (almost entirly). I swapped on another set of tires yesterday and went for a drive (I wanted to rule out the tires). No vibrations when I hit the brakes when on the freeway. Then, I rode the brakes for about 10 seconds and the vibrations picked up. Within another 10 seconds of riding the brakes, the vibrations turned to Death Wobbles. When the brakes cooled down, no more vibrations. All I can think is one or both of the rotors are warping when they get hot. Both were new a while back. Both are smooth. I did have vibration problems when I put them on and ended up returning both, but they still had lots of meat. I have 4 other 1 tons with the same rotors and have never had this problem. Some with larger tires, so, you know the brakes are getting worked even more. Any ideas what could be causing them to warp? Poor quality metal, internal cracks?? I'm going to repalce both of them, I'm wondering if any brand is made of better metal than others? EGR sells slotted rotors, do they really disapate the heat any better than flat rotors? Thanks, Eric M.