There is a little bit of a side story that goes with changing the stock mesh to a paper filter. Those mesh filters, when clean, flow a pretty good amount of air. They flow more air then an equivalent size paper filter. So you may end up with a motor that is running worse on a paper filter then on the mesh filter vis a vis less air flowing through at any given time. So you might have to mess with filter area size, stacking tow up, or just using a physically larger air filter, to get one that is just right, not too free flowing but not too restrictive, or as in the three little bears, one that is just right, lol. Do not know if that would be the case with a high flow like K&N.
The other thing to consider, and only if you are using the canister/air chamber style air filter, is that the inside of the canister /air chamber was not painted or protected when it was manufactured so rust has developed over the years. Also, the mesh filters were not all that efficient so its not uncommon to have a lot of rust, dirt and other debris trapped inside the air chamber. Because the air chamber itself is not accessible unless you cut the air cleaner apart, you cant clean all that junk out. If you take the air filter and lower lid off, then shake the canister, you will hear if there is a lot of junk floating around. If there is, you might consider getting a replacement as you probably don't want the motor to inhale that junk.
