I wonder…
I've thought about this, too, but my thought was to start with an S600 and an R350. Pull the M275, rebuild it as mild or wild as desired, shoehorn it into a stripped R350 chassis, and pin that throttle as often as possible. I think this route has better smiles per dollar.




There isn't enough clearance to the back of the radiator for the longer V12 engine. I'm assuming you would choose the M275 of the same era as the R Class but I believe all V12's since 1998 have the same overall length. The radiator will need to be relocated to clear the accessory belts.
You'll also need to consider that the M275 was never paired with 4Matic and retained the more robust 5-speed transmission. Perhaps you can upgrade the 7G transmission to survive the extra torque but this decision can't be ignored.


