1937 Dodge 1/2 ton Truck Front Brakes - Rear of Backing Plate.
Aftermarket bolt-on front disc brake conversion kits (kit includes new backing plate) are available from www.UglyTruckling.com. Surprisingly, their kit made for the 1961-1971 Dodge Sweptline D-100 Series pickup truck will bolt onto a stock 1936-1938 Dodge half-ton truck (pickup, panel truck, etc.) WITHOUT modification to the 1930's Dodge . . . the only part that 1936-1938 Dodge truck owners have to fabricate is one bushing for the base of the spindle to size up to the ID of the bearing supplied in the kit (easy to fabricate this part from stainless steel tubing at any local machine shop).
For very detailed installation instructions with step-by-step photos, see: www.uglytruckling.com/Sweptline%20D%20Series%20Trucks/Sweptline%20D100%20Front%20Brake%20Manual1.htm .