So i checked it out today. Took it for a ride and and here is what it does. It is deffiently MPH related.In fouth gear at anything over 3k rpm is vibrates like MAD. Its smooth as silk UNTIL that speed(probably around 60mph). The vibration resonates thought the driveline and will not go away until the car starts to slow down. If I pop it in neutral it has 0 effect.

I tried checking my pinion angle,not really sure where to exactly measure but i ended up putting my angle finder on the drive shaft and got -3 and then i put it on the pad where the pinion snubber is and got +3. Not sure if thats good? I ended up flipping the drive shaft 180 degrees in the yoke that did nouthing. SO then i figured let me try and put some shims under the trans mount to move the tailshaft up, Put about 3 fender shims under the mount and took the car out, made NO difference.

Im really not sure where to go from here. This car was so smooth with the automatic right before i converted to the manual. When i converted to the manual i used the correct 68 crossmember and mount, the SAME driveshaft that I had with the auto. I used all correct Mopar fastners for the flywheel and pressure plate. A reconditioned flywheel from Brewers and a new DF Centerforce clutch , all new linkage etc.

Pilot bushing is new also. I did not do any alignment with the bellhousing, i just bolted it on using the factory dowels.

This is a CRAZY vibration,like when it starts to vibrate, you have to back RIGHT off the throttle. makes about the same racket as if you were in a car and it spit a ujoint.

Any suggestions Please help. Im not sure what to do next?