I have been setting the timing to factory settings but it seemed to idle badly and sometimes it backfires into the exhaust a little on deceleration. I decided to advance the timing a little and see if that helps. I bumped the timing up about 3-5 degrees. After adjusting the idle mixture the car seems to pull stronger and run better with no sign of abnormal combustion. I might try to push it up a few more degrees and see what happens.