I'm doing the Nyroc muffler mod. and I'm also going to drill some holes in the air box lid. What after-market air filter do you recommend? And what jetting to you recommend with these modifications? I ride at 1,500 feet elevation.

 

I use the uni filter(I like it so far) I had the K&N but always would have dust in the airbox ,if you go with the K&N grease it up around the flange it does`nt seal very good.Jetting is trial and error,I have the muffler mod and napa snokle mod ,I am currently 148f 150r (little rich)needles shimmed with#4 washer and a small washer from a dyno jet kit I`m at about 950 feet elevation.

 

Bead of low temp silicon around perimiter of bottom edge of K/N filter, pop it in place, install top cover, clamp down and let cure.
Area under my filter is squeaky clean. I/m also running Webb Cams plus the mods in my signature & jetting is stock pilots, Dynojet needles on 2nd clip from top with 145/145 Keihins main jets. Plugs are light brown after throttle chop

Each bike is different, just got to find what it likes best/runs strongest with your mods.