I imagine the guessing is over but Bob Caser is the closest.
It’s hard to substantiate as there have been SO MANY interviews with Caroll Shelby but way back in the later part of the last century, Shelby was interviewed concerning the original or the initial prototype of the AC Cobra. He talked about how they were putting something together which would evolve into the Cobra. He mentioned that the rear end was taken from a Studebaker and fit into the AC chassis. Being that I was and still am, an avid Stude guy his statement has been imprinted in my mind. An even closer match to his statement at that time is “the rear end came out of a six cylinder Studebaker”. Im sure Caroll Shelby, like Andy Granatelli, liked the lime light and enjoyed his time on stage. If he used a model 27 Dana it sure wouldn’t have lasted through one hard shift but if it was dimensionally what he needed at the time he, at least, would have a roller.