Do you have a thermostat in your system Chuck? With the stock oil thermostat my car hits 167F (75C) relatively quickly. I think it takes about 5 miles at 50-55 MPH...almost twice as long as it takes coolant temps to hit 167F with the Mugen thermostat. After that oil temp creeps up to 176-187F (80-86C) where it usually stabilizes.
Eric, if I remember right Chuck has a dry sump oil system. Quite trick!
Jim, the part number you're looking for is 00642-16401-002.
