[QUOTE=ltwargssf;7377054]just swap a 6.2 in it, im waiting for my m272 to blow so i can put a m156 but that 3.0 is strong and I don't see an end in sight ,even with 240k on the clock. These aren't cars with a crazy aftermarket tuning available, at least you have a 3.5 in yours, a simple ecu tune will get it to 300hp, they just detuned the c350 3.5 in those years for the c300, 1: you cant put a c63 engine in a c300 you will literally have to buy the entire front end of a c63 for that to work... idk about the m156 i havent done research on that but yea the c300 and c350 do have the same engine CODE however not the same engine the 3.5L has approximately 500 more ccs in displacement then the 3.0L so the c300 m272 has just under 3000ccs while the c350 "m272.5" Is what i like to call it has just under 3500ccs now will a 3.5l fit in a c300? Yes direct bolt on literally everythings the same except the displacement but i do wanna know more about this m156 swap im interested lol