Just a post on my 124. Similar issue ~ called S&S and they recommended Cycle-rama in Pinellas Park, FL. Took it to Wes. Diagnosis, the idler gear bushing was wearing and the noise I was hearing was the Idler gear moving around in the camplate. No loss of oil pressure or performance just alot of noise, and I could not isolate it. Wes called S&S they are replacing lifters, camplate, oilpump and the cam chest cover. Wes stated the 640's were fine. About 6k on the motor but the noise had gotten louder with time. I had pulled the crank position sensor and there was no metal so I felt like the cam chest was the most likely offendor. Love the motors power, and hope moving forward for a bulletproof 124. I guess only time will tell.