This was the one sold by Chevy. Found on page 434 of the 1929-1954 Chevrolet Master Parts and Accessories Catalog. Listed below, 7.503, Spring Assembly, Rear section, 47-54, Util, 6 leaves (Aux Springs) Part 604934.
Phil Moderator, The Engine Shop, Interiors and Project Journals
1952 Chevrolet 3100, Three on the Tree, 4:11 torque tube Updated to: ‘59 235 w/hydraulic lifters, 12v w/alternator, HEI, PCV and Power front Disc Brakes Project Journals Stovebolt Gallery Forum