I have the Luke's Racing 450cc kit that uses a sleeved OEM jug. I am getting trace amouts of oil in my coolant. I suppose this means I need to change the head gasket. What head gasket do I use? Will the RMZ450 head gasket work? What about the base gasket? Does it use a stock base gasket, or do I need a different base gasket for the larger sleeve? Bike still runs strong, starts easily, idles fine.