I have down extensive research on mods for my 09 Street Glide and I have already installed the TFI. It makes a difference on the stock bike that you can feel seat-of-the-pants. The new SE Fatshotz are made by Supertrapp and are tuneable. More discs for mid range and noise, less disks for low end torque and quieter. The TFI will allow adjustment for either. I also went with the the Ness Big Sucker. Will have all mods done by next week, SE 255 cams to follow over the winter. Good luck with your mods