Not sure if this helps because I don't know if AD parts will work on a '57, but these numbers are supposed to be good for AD trucks.
New Departure Front Inner Bearing #s
1946-1953 passenger car and 1/2 ton truck, 1941-1942 passenger & commercial
909552 Outer Race
909602 Inner Race
909702 Inner Bearing
New Departure Front Outer Bearing #s
1946-1953 Passenger and 1/2 ton, 1929-1930 All, 1931-1942 Passenger & Commercial (exc. CC, DC, EC, FC Models)
909501 Inner Race
909601 Outer Race
909701 Outer Bearing
Wheel Seal Original #s for the Inners for 1946-1953 Passenger and 1/2 ton trucks with Felt seals and Retainers;
GM part # 3656536
