All of the mercedes engines of that era tended to be fairly close in weight. From the lightest 4 cylinder to the heaviest v8 only about 100# difference. The v8s tended to be aluminum, the sixes and fours iron with aluminum heads.

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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.