After reading posts until I saw double, I have a few questions specific to my 93' SHO. As the second owner, I cannot attest to the care and feeding of my vehicle. It burns no oil after 148K mi, and has no ticks,knocks,or troubling noises. While doing a valve cover replacement, I did notice what I would consider minor residual discoloration in the valve train. What oil/filter would you recommend to keep things as clean or cleaner? What about using an oversize filter, FL-1A or equvilent? I only drive the car from May to November, so as to spare a very nice car from the "Frozen Tundra" of Wisconsin...Thanks in advance