The 1962 Chevrolet 235 rear rocker arm assembly is not getting as much oil as the front rocker assembly. Oil is poring out of the front assembly and out of the last rocker arm but not out of the second to last and third to last rocker arms. Also cylinder number one rocker arms have air bubbles coming out them. I had to take the rocker arm assemblies apart and clean sludge out of the shafts and the rocker arm oiling holes. Then reassembled them with rocker arm oil holes facing down. Could the shafts just have excessive wear causing the oil lose to the rear rocker arms?