I think economy of scale is about right. My dad used to say that GM could put them out of business any time they wanted to as they owned so many of the companies that made parts for stude such as diffs and trannys.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.