The rotation doesn't matter. It matters is you have roller rockers or not.
The common non-roller rocker chevy hydralic lifter adjustment is to loosen
the the rocker, tighten the rocker while turning the pushrod until you feel
resistance. Then turn the lock nut an additional 3/4 turn down to center
the lifter plunger. The merc service manuals like clymers, etc will also
have this and the roller rocker adjustment procedure. Plus any other
specifics related to your engine and the valve train. It's worth the $25 if
you are going to do your own maintenance.

Hydralic valve trains very seldom need adjusting. Unless it has been
disassembled. Usually noise is a sign of problems.

wrote in message
oups.com...
I am looking for the valve adjustment procedure for a 454 mercruiser
counter rotating engine.