valve adjustment?

The rockers aren't adjustable. The procedure you're describing is for stud mounted rockers. If you have pedestal mounts (stock) it's different.

Rotate engine so both valves you're working on are closed (lifters on the base circle of the cam). Install the rockers and hand tighten the bolts til there is zero lash (no gap on the valve stem side or the push rod side). Once at zero lash, then torque the bolt to 17-20 ft-lbs. while counting the number of turns it takes to get there. It should hit the torque between 1/4 turn and 1 turn. If it takes more than one turn to hit the torque after zero lash is reached, you'll need to shim that rocker up with .030" shims - each one reduces the number of turns by about 1/4. If you hit the torque in less than 1/4 turn, then you'll need different length pushrods.