Usual procedure with Oilite bushings is to knock the old ones out with a hammer and suitable drift. Then install the new ones with a stout fine-threaded draw bolt and flat washers to pull  them in nice and straight. Something like 1/2″ or 9/16″ UNF should do the job. The fine thread applies more force than a coarse one and seems to make things go easier.

If the new bushes are tight on the shaft after installation, you can ease them with a good sharp reamer, according to the Oilite instruction literature.

No oil hole usually needed because the bushing is porous. But if the original Myford bushes you take out have holes drilled in them, I would do likewise.

Quite a few years ago my S7, bought second-hand but unused, suffered from vibration on the higher primary belt speed although OK on the low speed range. Seems that it was due to a less-than-perfect V-belt – slight imperfection at the join or somesuch. I changed it for a link belt on the advice of someone-or-other and it completely cured the problem. No slipping problems either with the link belt. Just a thought.

Could be the clutch and pulley unit out of balance too. Maybe due to wear? If bearings don’t fix it, you could mount it on a couple of ball bearings and balance it by drilling holes in the heavy side. I would balance the inner hub unit as one piece and the outer pulley unit as another.