Can not adjust valves correctly. Always hear a ticking after adjusting. When adj. intake/exhaust for #6 cylinder, it goes as follows: I loosen rocker adj. nut till rocker rattles,i tighten till it stops ratteling, I tighten another full turn and after approx. 6-8 revolutions the ticking returns, I tighten another quater turn,ticking stops till another 6-8 revolutions,ticking returns! I have replaced oil pump with a high volume pump, replaced camshaft w/new along with new lifters,please help!