I have Comp xe 268 cam in my 355 with roller tip rockers. One rocker started ticking after about 1000 miles or so. Adjusted it was fine. Took car for ride [ over 2000 miles ]first time this year same one satrted ticking. Seem to do it when it was hot. So adjust it again. My biggiest fear cam lobe going bad. Called Comp Cams and they said that lobe going bad. The car runs fine and pulls real hard. I would think after 2000 miles car would start missing.