Did you take a thin wire and run it through each rocker arm passage? It either that or using a can of carb cleaner and the straw spout to run pressurized carb cleaner through each passage to be sure they are open. Each rocker has two passages.
Also did you remove the cup plugs from the ends of the rocker shaft and brush out the inside? That also is important.
Loctite in the replacement cup plugs.
And as mentioned previously, on mechanical rocker arm motors you can put the shaft in the wrong way. The small hole on the hydraulic slant six shafts helps to prevent that on the hydraulic motors.
But yes, all of the rockers should be oiling, if not either some passages are blocked or the shaft is installed wrong.
