valve lash

Lash would be zero, pre-load how ever is............do you have an adjustable rocker set up, or adjustable push rods? I would start with 1/2 to 3/4 turn after zero lash, experiment with what the engine likes, maybe tighter, maybe looser.

If you don't have adjustable valve train, bolt the rockers down and go; maybe shims under the rocker shafts and pedestals, again experiment with what the engine likes.