Okay, I got a 66 mustang with a built 302, I know this isn't the engine that was originally in it, but this car was made for the drag. My question is, I had to replaced my valve cover gaskets, since they were leaking, and Iv'e been hearing my valves ticking lately. So I figured I'd go ahead and attempt to adjust them. This engine has aftermarket parts all in it, It got some sort of aftermarket cam, it's got a lope sound to it. I dunno what kind. I believe it to be a solid lift cam though, since the valves are adjustable. It's got a hex type screw in the rocker arm, and a nut on the outerside. My question is, I was just screwing around a little with the rocker arms, I attempted to adjust the no 3 intake and exhaust valve by tightening it. Man, did I make a mistake, I tryed to start it, and it would turn over, but it would never start. So I keep messing with the valves on that cylinder, and still no luck, and once I had the carb on fire from messing with the valves. So Im trying to figure out how to get the car back to running now? It wont run or nothing, and it acted like it wanted to kick back a little, while I was starting. How can I adjust these valves for the car to run? I dont have any specs whatsoever on the cam. Maybe yall could give me like what number on the feeler gauge to adjust them to or what? Please help. UPDATE: Not too long ago, I adjusted the the no 3 intake and exhaust valves to 0.018 on the feeler gauge, and it started up and ran fine. So I thought I had it right, but then after about 10 mins of running I heard the valve that I adjusted im guessing it started chattering really loud, and felt like it was losing some of the power. But im guessing I dont have them the no 3 valves adjusted right. Can some one please tell me how they normally adjust a built engine with an aftermarket cam like what number for the feeler gauge? It would help a lot. I noticed that on this engine the valves have to be adjusted right, or it will not run at all. Serious answers please.