I have a 99 2500 burban with the 454. It shakes when braking and I believe that the rotors are warped. I heard or read some were that it can be a contueing problum. To add to the issue I tow a trailer through out the states that can weight in the 9,000 lb range. I have read a little about drilled and/or slotted. Any real life info out there?