Changing the 617 for a 603 is no upgrade in my book.

The 603 is a little more powerful and a little smoother but the fuel economy is about the same really.

The 617 is as bullet proof as you can find excepting the 616 and 617 non turbo motors.

Tom W

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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.