Hey guys. Got a puzzler for you. My 99 RT, 75k miles, has developed a pretty strong vibration at higher RPM's. So far I've rebuilt the transmission and replaced the clutch pack. While I was in there I checked the fly wheel for any movement, its solid. Throttle bodies are balanced and the valves are set. I also checked the alternator belt, that's ok too. When I'm doing 75 mph, pull in the clutch and drop the RPM's the vibration stops. Increasing the RPM's again with the clutch still in the vibration starts again. Any insights will be greatly appreciated. Thanks, Gregory