With just a K&N filter swap, you shouldn't need any adjustment, but you could benefit by adjusting the air/fuel mixture screw out a bit to richen it up, as these bike are known for being lean from the factory. If you do this it is best to get one of Glen's permanent A/F adjusters and install it and then you won't have to take it apart again just to make an adjustment.
http://glensvtxgarage.com/aftool.html
If you go with Spykers kit you can get away with doing the scar mod.
I decapitated my airbox and then did Spykers cover mod, so I went with a factory pro jet kit.
Here is a link to the Scar mod. However don't cut the factory spring down.
http://www.vtxcafe.com/showthread.php?t=1914
http://glensvtxgarage.com/aftool.html
If you go with Spykers kit you can get away with doing the scar mod.
I decapitated my airbox and then did Spykers cover mod, so I went with a factory pro jet kit.
Here is a link to the Scar mod. However don't cut the factory spring down.
http://www.vtxcafe.com/showthread.php?t=1914