I agree with Tim's point. Sounds like there is a an issue causing the vibration. Similar symptoms prior to my pinion bearing exploding. If your going to take it all apart, do it once. I did mine years ago, have many trouble free miles since.....

SWEET
Sergeant At Arms: Old Dominion Stovebolt Society
BUNS?!?!?!Where we're going, we don't need no buns.....
1950 GMC 450
1951 Chevy 1/2-Ton
The GreenMachine
In the Stovebolt Gallery