Sorry for this, but I had posted the issue before elsewhere and did not get any responses other than referrals to the Technical Manual and confusing explanations. I did not want to crowd the forum with my petty queries. Here I go again:
I have an car that was produced in December of 1970. It has the original engine in it. It was ordered by a German in Germany and sold there, until I brought it with me to the U.S. in 1988. I am the 4th owner and own the car since 1982. It has a well documented history.
The cylinder head casting marks say 280SEL/SL with a casting number of 130 016 17 01 and a compression of 9.0, none of which I have seen anywhere else. The Technical Manual does not show a head of this variety. One of the theories given to me was, that the late production run was such outfitted to meet some emission regulations (although I am not aware of any changes in Germany during that time that would make it necessary). I was trying to find cars with a close production time to see if that was the case. No luck, however.
