1st gear vibration

[LB1951]

Posting for a buddy, 67 Barracuda 383 4 speed has a bad vibration taking off from a dead stop only at low RPM shift into 2nd higher RPM and it starts to go away 3rd and 4th no vibration. Had the tranny rebuilt and clutch, pressure plate and bearing are all new. Vibration is so bad it shakes the dash. Anyone had a similar issue?

 

[Xcudame]

Vibrations are usually caused by 1) something out of balance, 2) something loose or 3) something wearing/worn out. First thing I'd do is check bolt torques on everything and look for loose.