You might consider purchasing a service manual before you do just lifters. How many miles on your Buell? IMO the Buell without a traditional frame makes top-end rebuild a breeze. Might as well replace all moving parts if you are going in. Takes no time at all and you get the compression and performance of a new engine. I took a few days this winter and it's very easy and satisfying work. I don't think all these parts needed replacing but parts are not that expensive. The pistons costing the most but I could have used the ones here with just new ring kits. Break in is done and I'm confident the top-end is quiet and solid now. I have little experience with Harley engines but on the Buell it's by the book, no surprises, and compression is now well over the SM's requirements. Plus you can check the valves and get that done and off your mind if you feel the need.