I've adjusted the valves 3 times now and still have a rythmic tap-tap-tap that is RPM dependent coming from the valve-train. I adjusted one set of valves at TDC and then rotated 360* and adjusted the other set - all while the engine was HOT but not running. .008 intake .014 exhaust. Is it possible to adjust the valves correctly and still have chatter? I have what sounds like a single rocker clacking away - more so at full throttle. Could a bad pushrod or rocker arm adjusting screw cause this? I didn't want to over-tighten things. I still need to narrow it down and identify exactly which rocker is making the noise and then go from there. I tried to find it with the engine on and it squirted hot oil at me so I shut her down and performed the adjustments with the engine off. I may try to check it again with the engine running again later.