Bad Vibration: Transmission Bearing? Flywheel? Leaperchauns?.

[krazy00kanadian]

Some may remember my thread a few weeks ago where i replaced my clutch because of the T/O bearing. Everything went swimmingly, and the clutch you all recommended fit perfectly and worked well in the shop but...
First time I took it for a drive there is this shake/vibration which rattles the whole car at around 45-60 MPH (70-95 KPH)

Lets get the facts down:
1. Not a steering thing, very obvious. The wheel stays very steady and the car does not pull left or right
2. Feels very deep rooted in the car, drive train or transmission
3. Accelerating or braking in any gear (within reason for speed given), any RPM
4. When clutch is disengaged, at speed, vibration dies down slowly.

Is this my flywheel? or could it be something in my tranny? My friend thinks a bearing could have been knocked loose when the T/O bearing went, but I only drove it at most 40 miles.

I am afraid my knowledge on this is not nearly up to par to diagnose this problem. Anyone have any ideas? This happen to you?
~Farley

[philbyil]

Check the following :
The driveshaft was refitted but at 180 degrees out....(more likely)!
And, how were the condition of the guibo and center bearing?