A set of stock hydraulic rocker arms, shafts, and pushrods. They can be found on any 68 up 273, 318, 340, or 360 till he magnum engines. Just clean them up, inspect then, oil them up and bolt them on, Done. Just make sure the shafts are oriented correctly. The rocker system changed again with the magnum engines in the 90's to pedestal rockers.
I wouldn't use the later hollow push rods that came with the roller cam, but, yeah, find a clean set of LA small block rocker assemblies and matching push rods, or, get custom length push rods for your adjustable rockers......your choice.