Getting zero lash

Hand tighten rocker arm
are the pushrods supposed to slightly spin or does it need to be snug before preloading? (#1 cylinder tdc)

1/4 turn equates roughly to .1-.12 preload so 1-1/4 or 1-1/2 (turns till 22ftlbs) would put me around .7-.8 preload?

The rocker arms came with stud mounts and shims. Ho do I know to use the shims or not?