[Milepost]

I usually do a drain and refill with the same kind of breakin oil after a few hours of running the engine. I will also do a recheck of the valve clearances, do a retorque on bolts/studs at that time. BTW... I cut open the old oil filter to see what kind of crap was left behind when it was opened up. Don't be surprised to find some lint and some very small non magnetic chips in the filter. First couple hundred miles I drive arond town or winding country roads, making sure I downshift thru all the gears to load and seat the rings. I then progressively run it harder and harder the next 300 - 500 miles and change out the breakin oil at 1200-1500 miles and then put in the synthetic oil. Be sure to cut open the filter again ... It should be pretty clean by then. If it looks trashy send in a few oz of old oil in to be analyzed. A good lab can tell you where the debris is from such as bearings, rings, pistons etc....