:When I adjusted my valves, @153,200 miles (I've only had the truck the last 1500 miles) I noticed that if I moved the rocker arm forword or back it would tighten up the valve lash, the adjustment was fine when the middle of the rocker lined up with the valve. Is this normal? Is this a sign of premature wear? Let me know if anyone has had the same experience.

 

<br> The valve stem has probably worn into your rocker arm, where the rocker pushes on the valve to open it. When you move the rocker to the side, you have an unworn part over the valve stem, hence the lesser clearance. <br> BIG MIKE ;D ;D ;D