20 -25 ft lbs on the shafts , DO not over tighten them , I have seen totaly distroyed engines all caused by overtorqued rocker shafts
adjusting the rockers is somewhat complicated , basically rotate the engine & wait for an intake valve to close fully & set the exhuast for the same cylinder using a feeler guage to measure the lash the feeler should be snug to pull out , work you way through the firing order then go back & watch for the exhaust to just start to open & set the intake valve again working through the firing order