I have an original '73 240z with 30k original miles. It is in excellent shape, no dash, cracks alloriginal hoses under hood etc. I am in the middle of a tune up and had some questions about the air cleaner. My air cleaner has two holes, @ 1" in dia, in the curved end of the cover that look like something attatched to it at one time. What are these for? Also someone installed a K&N air filter but it appears too thick. The cover won't seat against the back plate when installed with this filter. I picked a replacement filter at my local shop and it too was too wide. is it possible that I have an air cleaner from a 260? the prod date on my car is 2/73. any ideas wouild be appreciated.