Might be a 4 speed issue but many more viewing this forum. 64 cuda with 69 dart gts drivetrain (340 4spd 83/4). I have developed a bad vibration at 3000rpm and higher. It gets much worse when I depress the clutch while driving at these rpms. No noticeable chater/squeal or slipping from clutch. Maybe a little less vibration when first driving cold (hard to tell). At least a couple of thousand miles that I know of without the problem. No noticeble vibration when the back end is of the ground and no movement from the dampner. HELP?
