I have a 98 FXD. It has stock carb and intake with SC 2 slip ons. I am going to install stage 1 breater. I followed a link to Harley Performance.com. They have a basic stage 1 tuner kit that includes CVP slide needle, two main jets, two pilot jets, drill bit to access mixture screw. They do not specify jet size. The price is $20 shipping included. I live at about 3k to 4k above sea level. Worth risking the $20 bill?
Check out the posts in this section. Lots of good stuff there that may help you make a decision. Fuel and Carb Related Issues - Harley Davidson Community TQ
I put it in my '97 Heritage when I bought it and noticed a difference but I put a K & N filter on at the same time. IMO, worth the cash but get the filter too.
Yeah..free flow breather, SE or Ness Big Sucker and the Stage 1 Basic jet kit is all you need,along with your free-flow pipes,well worth the $20.It'll wake up your Evo.