You'll find a performance subforum here. As for something which will bolt in in place of the 617 turbo, no, really there is nothing that is easily found in the states which will. I believe there are some small Japanese diesels which will fit found in other markets though.

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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.