I just picked up an 81 Euro 280sl. The car is cherry, runs great and the price was right. Going thru 26 years of repair invoices I saw that the differential had been swapped out at some point in it's life. Does anyone know what the proper final drive ratio should be on these cars. If not what rpm are you turning at 60 and 75 mph. This thing is turning about 3500 rpm's at 75mph. Is this normal? I'm not used to engines spinning at such high rpm at such slow speed. It is however as smooth as a Swiss watch.

Thanks Matt