Have a newly rebuilt 261 in my '56 pickup--3 spd OD w/ 12 bolt posi. Engine was magnafluxed, bored, head shaved, balanced, clutch, flywheel, throw-out bearing balanced as a unit (just pulled cover and rechecked to so if installed according to machine shop markings--yup). Both front and rear seals seem to be leaking since firing it up and experiencing vibraton. Just sent harmonic balancer in for restoration as was not done during rebuild (not back yet).
Symptoms--vibration when engine revved, feel significant vibration when releasing clutch, vibration most noticable at about 50 mph and gets much better at about 60 mph.
Looking for answers. All input appreciated.
