[DAVID GAGNARD]

I set them before starting the motor(just as the others have advised), do a 15 to 20 break-in and then shut things down and let things cool off a bit......

I took an old factory steel valve cover years ago and cut out a strip about 2 inches wide in the top, the length of the valve cover.

I then install this valve cover on one side, start the engine and begin re-adjusting each valve........First I loosen one nut at a time till I hear the valve "ticking" and then slowly tighten that one, when the "ticking" stops, I add 3/4 turn and go to the next one.......

works like a charm, have one 351-W I did this on 6 or 7 years ago and the valve covers have not been off since...........

David