I would imagine a '66's front wheel bearing info could be located at a parts store even though they won't have it in stock(?). RockAuto stops at the GMC 3500...parts link
Check out the GM Heritage Center , and Kieth Hardy's OCMP.
Welcome to Stovebolt.
Brad

(Also- you will probably get some specific answers to your questions... you can read in the manuals until that)


Wrench Fetcher, PhD