When I got my 89, it was obvious that the prev. owner had not changed the oil as often as he should from the coke deposits in the valve cover and and the head. I changed the valve cover and disturbed some of that crunchy stuff. Afterwards, I had a lifter occasionally stick in cold weather. Frequent changes helped and using a filter with a good anti-drainback valve like Bosch helped too. When the oil drains out of the cheap filters at engine shutdown, the dirty side of the filter dumps to the pan. Try a good oil and a good filter and frequent changes and maybe if its lifters you hear, the trash will get blown out of the offending lifter-this is what apparently happened to me. Valve Clatter @124K - No valve clatter @144K. Use the lowest recommended viscosity for the temp range for a while.