For sure, engines have quirks, personalities, and histories. Part of getting to know (and love) my '66 230 is learning about the m180.945 that came with it.

For my class of car (110/111) I see that the straight six came in 4 displacements. Were these all m180 motors? Also, what characterizes the differences between the last three digits in the motor number? Were all the 180s alloy heads? Are all the heads interchangeable? Why does the 230 and the 230S have the same displacement and compression ratio, yet the 230S has more horsepower? Maybe the carburetion?

I'd love to hear from everyone having experience with these motors.

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1981 300TD 310k miles
1970 280sel 172k miles
1966 230 Fintail 162k miles

"Where are we going? And why am I in this hand basket?"