Going on from Waynes comments
If have after market rims, and drums, check that a rim is not sitting on slightly on one of the balance tags on the drum...
Check the balance tag is on the drum
And no paint between the rim and steel of the drum where it bolts up.
If have sloted rims ... use orginal tapered end stud bolts , tighten each a litle by little by hand with a slight knick up so the holes center on the bolt tapers... then remove each one , 1 ata time and replaced , torque up with the correct matching to rim bolts and washes.
If cragers , use the correct carger washers and bolts.
oops 1st question is the vibration in the steering wheel , or feel it in your feet or in the base /back of the seat?,, that will tell if front suspection or rear.
I suspect the tailstock bushing/driveshaft yolk or flex plate/torque converter, anyone got any advice?
If not in the steering wheel yes those are a good possilty...u meantioned new engine. So did these get replaced or still orginal?
Do they still have their balancing tags on them....I assume thenew engine was not dynamically balance from the harmonic balancer bolt thru to the flex and torque convertor....
Bit confused here.. u got the new Driveshaft balanced...that should have bee done with the new yoke and the universal joints all together?????