I have been searching for the postion on TDC for a 1987 300d OM603 engine. I want to make sure that I do in fact have it set to TDC before I install new head gasket and recondition head #20. When I pulled the head off the only marking on the crank shaft pulley was a PIN. I guess this is call a TDC generator pin with this pin in line number one and six clinder are up to the highest point. I stll have not recieved my CD to gather this information. Your help is greatly appreciated