I have a '06 Street Glide. I have been riding for many years but this is my first Harley. A week after purchasing my bike I had stage 1 upgrade and SE 1-piece mufflers installed. Just recently I had V & H Ovals & header pipes installed. I decided to sell the SE pipes. While cleaning them up I noticed that the part number etched on the pipes was different than what was on the Dealer's work order. The part number on the pipes is 64910-99 and listed on the work order is 64903-99. No where on Harley's website including the SE parts section could I find a reference to part number 64910-99. Neither could I find them listed in the latest SE catalog. But I did find 64903-99. Here's my problem. The only places I could find part number 64910-99 is on 2 aftermarket sites. http://www.surdykeharley-davidson.com/ and https://www.chicagoharley.com/2frames/2frame.html Both of those sites have the list price of part number 64910-99 at 159.00 but are selling them at a discount. They also both have part number 64903-99 listed at 319.00. My dealer charged me the list price of 319.00 for part number 64903-99 but installed 64910-99 listed at 159.00. I'm sorry if all of this seems confusing but can someone please enlighten me on the difference between the 2 models before I take this issue to the dealer? Do anyone know anything about part number 64910-99? Thanks.