Just installed, "K&N RK-3910, Filter Kit" on my '09 Softail Custom. The results so far... too easy. Took me about 4 hours to do from start to finish. That includes checking fit up of some of the parts, removal of H-D factory warning label, a few interruptions to answer the phone, and getting final approval from the Dog. Recommendations: 1) Shop carefully! Instead of buying right away, I did an online shopping search with the manufacturers name and part #. I paid a little over HALF of MSRP. 2) Read instructions a few times! Instructions are available online at the link above for the K&N product. I read the instructions before doing the install, I was already familiar with the product before I opened the box! Then, I read the instructions again. 3) Organize! I had tools gathered and laid out as well as the filter kit before I started. I had a table to my left with the tools, and another table to my right with the parts out of the packaging. Sat on a milk crate between the tables that put me at a comfortable level to see what I was doing. A lift table would have been better, but, I was able to "make do" with what I had. 4) Take the phone off the hook and have dog treats in your pocket. Minor notes: This particular filter kit stands away from the motor 3/4 of an inch more than factory. I've taken a few short putts around the block and I hardly notice it. "T" handle wrenches would have been a good idea but not necessary. I'm planning to give the new intake a good wringing out tomorrow along with some adjustments to the Dobeck EJK. Results to follow soon.