Reinstall pushrods in original positions, although theoretically they are interchangeable.

Reinstall rocker arm assemblies in original positions, taking care not to let the rocker shaft slip in the rocker blocks thus allowing the needle bearings to shift or fall out.

Loosely install the cylinder stud nuts over the rocker blocks, just finger tight. Make sure the tips of the pushrods are centered and fully seated in the recesses for them on the rocker arms.

Shown here are the older-style ('70-'81?) rocker arm assemblies, which require correct alignment. And note that the insert in the center of the rocker shaft faces up (on top).