How much of a difference will a K&N make on my stock blaster? Also, whenever i move it, do i have to rejet or move the clip any?

 

Probably not much of a difference if it is the only improvement you've made. The only way to tell if you need to rejet is to test ride at the throttle opening you normally ride at. For main jet performance that means 3/4 to full throttle. By "clip" I assume you mean the needle jet. The nominal position for it is in the 3rd position. This jet controls fuel flow from 1/4 to 3/4 throttle. The remaining jet is the pilot jet, which operates from idle to 1/4 throttle. The wise thing is to ride at these speeds for 3/4 mile or so & notice whether you have any missing or hesitations. If so, you possibly need to fatten up the mix at that rpm..the other thing to do is a plug read after a test ride. Normally, any lean condition will occur with the main jet so do your test on that jet, 3/4 to full throttle for at least a mile..lower gears are okay, the throttle setting is the key not the speed of the bike. after the mile, cut the ignition, stop & pull the plug. If the electrode & insulator are tan or light brown, you'r jetting is right on; if the color is a grey or light color, you are lean & need to use a fatter main jet. Black or sooty color indicates a rich condition. Odds are that you'll find that you are pretty much okay with the stock jetting until you do additional air flow changes to you ride.
It is always best to do this testing with a brand new plug so you don't get a false reading.