GM didn't reinvent the wheel when they built that truck. It's possible it uses the same hub/drum as a later model. I believe they went to Timken type bearings in 63. Have your parts store look up the later application. You also might even be able to find a used hub with bearings for a 63-66 at a wrecking yard.
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine