Originally Posted by quik

The flathead (adjuster) screws will not necessarily be parallell. As a matter of fact, it is extraordinarily unlikely.



The numbers listed are a safe range (although very small) for your valves' clearances to fall within. If your valves are too loose (i.e. you set them to the highest number, therefore the largest gap ) you will experience some valve "float"; your engine will be noisy ("wet", clicky) and perform poorly at higher RPMs. If your valves are tight (Example d15b7: 0.007" intake, 0.009" exhaust) your engine will sound smooth and perform better at higher RPMs.