Yes it is a M104 the difference is the head is bigger to accomodate 4 valves per cylinder rather than 2 as found on the M103. Also has variable valve timing. I had owned two 300E before, a 1987 black one and a 1986 gold (champagne) one, and when I bought my 1990 300CE I didn't know the difference and wondered why it was so big. The redline on the tach should be at 7000RPM and your photo looks like it is one of the earlier M104's as mine is. Mine runs just incredibly well, you will love it on the highway.
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