Well I have both a 220SE coup and a 280SE coup. I can check the numbers for you. But I am fairly sure that your transmission number is for a 220SE. The gearing for the two cars is different, if your are trying to find out what gearing you have. In terms of the rear end, 220SE had drum brakes, while 280SE's had disks all around. also mostor all U.S. 220SE's had 4.10 gear ration (stamped on the left side of the differential. while 280SE's had a couple different ones but most had a 4.08. I hope this information is helpful.

Michael
61 220SEb
69 280SE
72 250C