They're stud mount rockers, and they're not adjustable. You've got hydraulic roller lifters - so no adjustment is required; the hydraulic lifters do the adjusting. However, there is a proper installation procedure.
It's best if this is done with the engine hot. A pair at a time, rotate the engine so both valves that you're gonna "adjust" are completely closed. It's real important that the lifters are on the base circle of the cam when you re-install these. With both valves closed, down inside the stud is an allen-head lock nut. Loosen it up. Then loosen the rocker nut. While rocking the rocker with one hand, slowly tighten the nut until you reach zero lash - you can't rock it anymore cause there's no gap on the pushrod end or the valve stem end. From that point, tighten the nut another 1/2-3/4 turn. Then tighten the allen nut down to lock the rocker nut in place. Once you've done both, rotate the engine until you have another pair with both valves closed, and repeat until you've completed all 16. That's the proper installation procedure. If you've gone through that, and they're making a bunch of noise, or you can't reach zero lash even with the nut tightened, then the pushrod length is incorrect.
Good link - Crane has instructions for both stud mount and pedestal. Other than shims for the pedestal mounts, there's really no adjustment to make. The installation procedure is there just to let people know whether there's a geometry issue or not. For all stock components, most folks should be able to just bolt the pedestals down to the correct torque and forget about it. But when we start changing things (cams, heads, valves, pushrods, rockers, etc.) the procedure is necessary to highlight a potential dimensional problem that might have shown up with the new components.
302efi - go with what Michael said...I'm going to install my rockers, pushrods, lifters and all from Ed with my H/C/I swap...Ed gave me the right pushrods and all that...so if I just bolt them up like Michael stated...and then I'll be seeing how it performs