'68 289 Valve Clicking

[thunderbolt]

The valve adustments you saw were probably for a solid lifter cam which requires a feeler guage to set the proper distance. In a hydraulic cam, the rocker arm will always ride on the valve stem.
What you might try is this. With the engine warm (but not running) pull off the valve covers. Get a wrench on the crank so you can rotate the enging. Next watch each set of valves as you rotate the engine. As the intake finishes closing take the push rod for exhaust in your hand and try to rotate it. If proper preload is set it should not rotate easily. Next rotate engine until exhaust is just starting to open. Repeat push rod check on the intake rod. This opening and closing valve routien is to make sure the lifter you are checking is on a flat part of the cam. Note if your lifters are old this will not work well because they will pump down, but if lifters are in good shape this should work well.
Good luck