The pedestal mount rockers are not adjustable per se. The rockers, the pedestal height on the heads, the installed height of the valves and the pushrod length are all designed to work together to provide the proper geometry without adjustment. Go to Crane Cams website and download the rocker instructions - they are on-line.
Once the upper is removed (label all vacuum lines with masking tape and permanent marker), remove the valve covers. Start with the #1 cylinder (passenger front) and rotate the engine by hand (socket wrench on the crank bolt) until both valves are closed. If you rotate clockwise, the exhaust will open and close, and while it's closing the intake will open. Keep rotating until the intake closes completely - now both valves are closed. Remove the stock rockers on that cylinder. Install the new rockers. Hand tighten until there is zero lash (no gap between the rocker/valve tip and rocker/pushrod. Starting at zero lash, put your torque wrench on and tighten to 17-20 ft-lbs. while counting the number of turns the bolt makes. It should hit the torque spec in between 1/4 and 1 turn. Most people like them all to hit around 1/2-3/4 turns. If it takes more than 1 turn, you can use the shims that come with the rockers to reduce the turns. One .030" shim will reduce the number of turns to torque by about 1/4. Now, if you follow the firing order (find #1 on the cap, and just follow the cap order counterclockwise), the next pair will be closed with just a slight rotation of the crank.
When you reinstall your upper, use no more than 12 ft-lbs. torque. Once you've cranked it and run it through a couple of heat cycles, if they're making noise, you may have to go back through the same installation procedure with everything warm/hot. I find when I do that, mine run nearly as quiet as the stockers.
The rockers will interfere with the baffle on the oil filler neck. Take a look - you'll have to remove or modify it to clear the rockers. They may interfere with casting ribs inside the covers. You may have to grind those to clear the rockers.
The instructions above are the shorter version of what you'll download from Crane. Do not simply bolt them on - if you have any dimensional/geometry issues, they'll show up with this procedure. If there are issues, you don't want to discover them the hard way - by simply bolting them on, and cranking it up only to break something. In addition to the upper/lower gasket and valve cover gaskets, I'd buy new vacuum hoses as well. They are MUCH easier to simply cut off and replace with new hose. You'll also find installing the upper is much easier if you buy 2 short bolts at the hardware store that match the short bolts on the upper. Cut the heads off, and slot the end. Screw them into the front and rear short-bolt holes. They will act as dowels that hold the gasket in place, and make it easy to slip the upper in place. Once in place, start 2 of the longer bolts; then unscrew the temporary dowels, and put the rest of your bolts in. Particularly helpful if you're working by yourself. Good luck.
And yeah, it might be time to replace that pcv valve as well if you haven't. Get the screen too...it goes down in the lower intake and you can get it out with needle-nose pliars or a maybe a screwdriver after you pull the pcv valve out and grommet (black thing that pcv goes in) off.
