The M103 does have a single row chain, it’s less of a problem because the chain is much shorter than in a v8. The condition of the old head is a mystery and what makes it even weirder is that the machine shop, metric motors, told me the head was rebuild before and they were not sure if there was enough left to shave the head again, not that it mattered because the head was so corroded it was junk. Another interesting part, the car passed smog a month prior to taking of the head with flying colors. And I have a car fax report to back up the mileage, but I do have a suspension something is off. There could have been catastrophic engine failure and the replaced it at some time, metric motors told me I should have the later style M103 for a 1990 300SE.

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1979 Black on Black, 300CD (sold), 1990 Black 300SE, Silver 1989 Volvo 780, 1988 300CE (vanished by the hands of a girlfriend), 1992 300CE (Rescue).