"You don't need a tuner....."
by that I'm sure he's refering to a HD race tuner/super tuner, Power commander, etc. Those can tweak your air/fuel, PLUS timing. If you aren't going with a head job or major racing mods, there is no need to mess with the timing, only the fuel. That is why he mentions a XIED. A Dolbeck TFI, Fuel Pak, etc, is the same thing... a fuel management system. They allow you to add more fuel to the mix. You've already added more air with the new AC & pipes. If you don't richen the mix you will be running leaner than stock, and stock is already too lean (to meet EPA regs). Bike will run cooler too. Check your plugs. White = too lean, black = too rich. Tan is about just right. I ran a TFI on my 03 FLHTI and it made a big difference with SE AC & pipes. The dude at Dolbeck was one of the original designers of the HD Race Tuner. He saw the need for a less expensive option to only manage fuel. Everything else is pretty much a spin-off of his concept.