I have resently purchased an older boat with an inline 6 GM motor and a 165hp sterndrive. The motor runs well but I would like to change the bearings and oil seals in the upper gear case as the oil was very milky(more water than oil). On the upper gear case is a plaque with Model number 980705 and serial number W63364 but OMC New Zealand tell me that I there should more numbers and letters. I this correct as I cannot find anything else anywere. Please help!
