Dave, This engine has stamped steel rockers. The rocker mounts to a stud with a locknut. A hemispherical disk sits inside the rocker underneath the nut, which allows the rocker arm to pivot. Since it is a locking type nut it is not clear to me how to set zero lash. I also assume that the rockers are installed with the valve in the closed position, that is: the cam position is "off the lobe". Not sure what you mean by "ball and stud". Thanks for your interest.
Baldy, The engine is an Iron Duke which is a Pontiac 151 and used in the 1978-1980 Chevy
Monza. In my case the block is a mercruiser version (3 litre) with the automotive head. It is installed in an old truck. I purposely left this out of the post to keep it simple and try not to confuse people. I won't hold you to keeping track of what I am driving.
Best to all, Michael
