lbrowne, you're in Calgary, right? Go up to Mopac Auto Supply on 16th Ave N (about a block West of the old Brick on Centre St). They have a zillion different K&N filters up there. I wrote down the model# of several K&N filters I thought would work and they had most in stock. I think I use 3.5" as well and they have many different sizes when I checked a few months back. They've got a lot of cool stuff up there. I once scored a Flowmaster muffler at Mopac for cheaper than US mailorder places were asking BEFORE shipping and way cheaper than any other place in town. I also scored some poly endlinks and swaybar bushings from them cheaper than US pricing as well. They were the only place in town I could find with them.
Great store and excellent prices. If they don't have something, they can get it for you. That's also where I got some Powerslot rotors and Hawk pads. Most places I asked about that stuff in town had never even heard of Powerslot/Hawk.