Help! My roller rockers keep losening up. I have a 355 small block with dart II heads, and they have SI 7/16 rocker arm studs with 1.6 Harland Sharp roller rockers. I have a hydralic cam and my lash is a quarter turn after 0 lash. I adjust the valves using the firing order method (turning the crank 90 degrees and adjusting the next valve in order). I set the lash and then tighten the lock nut but it doesn't hold. Is there a specific torque setting for the lock nut. This is driving me bonkers.