If you will refer to your Star magazine about 3 mos. ago, a dealer reflected on the problems encountered with the w107 sl's. His dealership used to recommend replacing the single row on 380's every 50K. They later experienced failure on a customer's vehicle at 30K. Subsequently, they recommended going to the double row for all. I do not intend to argue the point. It is obvious what recommendations one will find from those that have any knowledge of the subject. By the way, the poor lady's 190 four banger will have to remain a single chain since the timing cover contains the oil pump mechanism.