Adjusting Valves on a 350

Running method: with the engine running and valve covers off (messy — lay cardboard to catch oil), back each rocker off until the valve ticks, tighten until the ticking stops, then tighten further: 1 full turn for new lifters, 3/4 turn if not too old, 1/2 turn if old.

Poly-lock method (hydraulic cams, from Rock & Roll Engineering):

1. Install the poly-lock hex-end up; thread the set screw in a few turns (hollow hex up).
2. Make sure the lifter is on the heel of the cam.
3. Push the pushrod into the lifter by hand to feel its spring tension; tighten the poly-lock slowly while moving the pushrod up and down, stopping just as the pushrod touches the lifter cup and the free play is gone.
4. Turn the poly-lock one more flat (1/6 turn). Hold it with a box wrench and turn the inside Allen set screw down to the rocker stud; snug by hand only.
5. Holding the box wrench, turn both together to ~25–30 ft-lbs — tight, but don’t overdo it.

Warning: you can’t properly tighten poly-locks by turning the Allen set screw alone.