I have an 06 Street Glide that cam bearing went out at just over 23K miles. It started making noise out on a ride this summer, it started whining like it had a gear drive in it, when it didnt, ended up being the cam bearing! After disassembly the cam bearing surface was scored, so I put 21G cams in it with the gear drive, new lifters/pushrods. Also, it scored my oil pump so I replaced the oil pump with a high flow pump and billet cam plate. Bike runs sooooo much better now with the new cams. I can agree with what someone else said, changing the cams the bike got really loud. I am running big shot duals and it is loud. On a side note, I changed the baffels to the Big City Thunder baffels and they made another big gain in the torque, and toned down the sound a little.