I have been trying to plan a Stage 1 for my Fat Bob. I was planning on buying slip-ons such as Rush 2.0 or Khrome werks. I really like and want to keep the look of the stock exhaust and headers. I was wondering if I will be missing out on significant power gains by not getting full pipes and headers (Vance & Hines etc...)? I do not care for overly loud pipes so sound is not the issue here.