The transmissions are all 1:1 in 4th, so that wouldn't be the answer. It is possible that the differential is different, and that might be original/correct, I don't know.
The original differential ratio in the '87 is 2.47:1. Perhaps somebody will know what the differential ratio should be in the '91 and the 300SE so that we can do the math.
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Gone to the dark side
 Jeff
