After completing a long restoration on my 67 Gtx 440 4/s I continued to have a vibration that was very difficult to track down , tried many things, with the helpful suggestions from the Guys on this site to no avail! The other day i was changing oil and filter and low and behold, looked up towards my motor mounts, saw that the mounting stud was to long and making contact with the block , which was making a pretty much solid mount out of them ! Removed mounts , clipped studs with a wafer disc , reinstalled, no move vibration ! FYI Hope this helps someone else ! Happy Fourth of July America!