[Dynomutt]

Might want to check the drive shaft length. If the motor was set back and the drive shaft length not addressed then it will go too far into the tailshaft. It will eventually destroy the back end of the trans and cause vibration along the way.

My post came out right after you said vibration was while not moving. OOOPS

Flexplate definately needs to be checked since one crank is internal balance and one is external. Might check harmonic balancer/dampner too.