well if you want to waste your money, be my guest. 3.5"
I bought a new filter on ebay, just a 3.5" conical flter, and it had red cloth in it, and I was told this was the same cloth that k&n uses, so i essentially bought a K&n filter for $5, under a different name. (the one that came iwth my kit was really small, plus my dog attacked the one that came with it before I got to install it.....lol)