Bill, are you wheel bearings tapered? If so, are you adjusting them as you would ball bearings?
I converted my original ball bearings to tapered roller bearings and adjusted them like one would adjust ball bearings, leaving a tiny bit of slop. That created a slight shimmy so I broke out my 1966 Buick Factory manual and found out they used the same type of roller bearings and the adjustment procedure was vastly different.
The instructions state that, as you are spinning the wheel, tighten the nut to 19 foot pounds, then loosen the nut, resume spinning the wheel and tighten to 5 foot pounds. This indicates to me that these types of bearings require 5 pounds of preload. That is quite different that what ball bearing call for, which is a specific range of a little 'slop'.
