The Dodge L1000 cab was designed by Dodge with input from Budd, and (acording to engineers from Dodge Truck) did not share with the Ford. The C- cab was originally produced at the Dodge truck plant but was later sourced to Budd when the light duty trucks (d series) introduced a new cab. Dodge produced components for their cabs that were produced at Budd. Dodge had a strangely unique relationship with Budd, at the time they produced Large trucks.
The Big Horn has always been one of my favorite trucks, there was a Black Dump truck that was owned by an independent operator here until just a few years ago.