Ron, Donald has it right, the kit you want from ECI is the EC 710 brackets and hardware only, or the EC 710CK complete kit with everything needed. Speedway has a similar kit listed as 910-31914 which will fit your '48 pickup spindles which take different wheel bearings than the passenger car spindle of the same year. These kits use Aspen rotors with the 4 1/2 BC.
I believe the Speedway kit is the exact item from ECI, but costs less.