These Brake Distribution Blocks will help you convert your single-chamber reservoir master cylinder to a dual-chamber version and features 2 In and 3 Out ports. Though primarily intended for 64-66 Mustangs, it will fit other Ford and Mercury applications through 1973 with minor modifications to the brake lines.This conversion will require custom-bent brake lines and the Brake Warning Light Sensor port is plugged.Please note: this is not a proportioning valve (P/N C5ZZ-2B091-R), which is required for front disc/rear drum brake applications.