I have a 1939 Dodge D11 with power disc brakes. There is a kit you can buy to convert to disc brakes. I will have to look through some magazines to locate the vendor. I found this out after fabricating a replcement backing plate to house 81 camaro calipers. I bought weld on brackets for rear axle. The rotors consist of a hat and rotor to fit mopar lug design. I bought an MP power brake system that mounts under the floor with proportioning valves and brake pedal. My car is unfinished as of now,but hope to complete this winter. I am running a 318 engine,904 trans and 83/4 rear end with 2:94 gears. I have used a tilt wheel from 77 chrysler cordoba. Looking forward to input or questions regarding 1939 dodge.