Rocker Arm Oiling

Pull the rear bolt and see if there is any oil coming up to the head first. If yes, then you may have the rocker shaft upside down. If no, then you have issues in the shortblock.

The early RAS rockers did not oil the valve tips well to start with, but you should be seeing lots of oil off the shaft.

No one will be able to give a definite answer without seeing the motor in person.