Very good advice DADMOD and your first post. I got the noted part DADMOD had referred to.
***Note: To provide the most accurate valve adjustment on hydraulic lifter camshafts, the heads must be machined to accept screw-in studs (on engines not originally equipped). On engines equipped with bottleneck type studs, using 270-99768-16 positive locking nuts will permit valve adjustment. For engines equipped with pedestal mounted rocker arms and hydraulic lifters, excessive lifter preload can be easily remedied by using Crane's rocker arm pedestal shim kit 270-99170-1. Crane offers a pushrod guideplate and rocker arm stud conversion kit 270-36655-16 for street applications, enabling the 1977-00 302ci and 351W engines with pedestal mounted rockers to have adjustable rocker arms without cylinder head removal or machining.