I received and installed my Pro Design air filter for the Griz yesterday. It would have only taken about 15 minutes to install the adaptor and all except that I had to trim the ribs out of the right side of the air box. The intake hole on the airbox is off-set to the right a little and the filter is oval shaped. I had to trim the ribs and turn the filter so the oval goes up and down instead of across. I also had to remove the tab on the air box cover that held the stock filter in place.

I haven't noticed any performance improvements but then all I did was change the air filter. At least now I don't have to worry about the cheesy stock filter failing me. Now I'm thinking about a pipe. Dang, I thought I was going to avoid modding the Griz.

 

What kind of filter did you get? I have the Pro Design adapter with both the Uni and K&N filter and had to make no modifications to the inside of the air box.

 

It's a Pro Design foam filter and has a second foam filter that slips over for real dusty conditions.

 

That's the one that came with the ProDesign kit. Should not have to do any mods to get it in, mine goes in without any.