I just got my 67 ss built,took it for a drive the other day ,ran thru the gears and when I hit 90 mph I started noticeing a bad vibrationit seemed like it was comeing from the motor,when u put the cluch in it went away.
Any body got any ideal on what might be causeing this?I have had the transmission,and rear end rebuilt also a new drive shaft.
Cluch flywheel ,harmonic balancer?

Start searching threads on vibration.It could be one of a hundred things causing vibration.Good Luck

Jimmy,
If it goes away when you push the clutch in, then it is probably not in the engine. Something from the clutch disc on back. What happens if you put it in neutral and rev the engine with the clutch out ? Does it vibrate then ? If so, if you push the clutch in and rev it does it change ? By the way, its not real good to be revving the engine a whole lot with the clutch pushed in, it puts a lot of stress on the engine thrust bearing, so dont get too carried away.

Just drive the speed limit and it wont be a problem :)

Thanks I will check this out

Just remember, the engine doesn't know what "speed" it's running at just RPM, if it was in the engine, it would vibrate in any gear at the same RPM.......

No vibration under 90 mph?

Could be a number of things. Maybe loose trans mount, loose motor mount, driveshaft out of balance, worn u-joint, heck even a flat spot in the tires could be the culprit.

I've been trying to chase down a vibration of my own, only seem to notice it at highway speeds once I hit 65-70 mph.