For use on street rod tube front axles when using '49-'54 Chevy style spindles, 9-1/4" brake rotor, 5 x 4-1/2" wheel bolt pattern, Pinto/Mustang iron calipers, 7/16"-24 inlet, Your stock Chevy spindles must be machined or use Speedway '49-'54 Modified Chevy style spindles, Not to be installed on stock '49-'54 Chevy Vehicle front ends. Will not work with stock '49-'54 steering arms.