I've got a 360 that when built, the machine shop had the exhaust valve guides too tight. During cam break in, it hung an exhaust valve, and bent a few push rods on the exhaust. I put a different set of heads on the motor, and ran it, because the lifters looked OK at that time. The car was then driven about 150 miles. At this point, there was a bit of valvetrain noise. I have 273 rockers, figured they loosened up a bit, and readjusted them. I was also fighting an issue where the engine was breaking up pretty bad over 3000RPM. Put another 100 or so miles on it. At this point, the voltage regulator went out, and I parked the car until last week. This week, I have put maybe 10 miles on the car, and it developed a pretty bad clunk in the top end. I have the rocker as tight as it will go, and there is still play. It also happens to be the exhaust on the cylinder that had the valve hang. Car runs like garbage, and there is glitter in the oil. I'm fairly confident that I have a flat cam lobe, but I won't be able to pull the intake and get a good look until I am home from school over Thanksgiving. Any good ways to tell for sure? If it is a flat cam lobe, I'd like to start looking for a 5.9 Magnum to drop in the car over break, so I can drive it until I have the time and money to build something a little hotter.