The discussion regarding the use of ZDDP in another thread here got me to thinking about the information that was compiled 7 years ago by Bart Como ~ bcomo, who used to own a 430MEL Squarebird. That information on which brand of oil is preferred by our members for their Tbirds is in the Technical Resource Library in the Oil & Oil Filters section. The thread concerning the discussion regarding which oil filter is the best one to use is not, although there is a different link to it that discusses this. You might want to review the thread where it was discussed regarding which oil filters to use and which to stay away from by checking this link, starting with Post #11. Perhaps it will be helpful to you. Note that the first two links cited in this discussion are no longer available though. The last two are.