29tons, the rocker arms and the feed tube changed in 1959. If you look inside one of the rocker arms, the oil groove for your engine should be in the center of the hole that the shaft goes through. Starting in 1959, the oil groove moved off center. The difference will be obvious when you look inside one of the rocker arms.
If you have a '59-'62 feed tube, you might have the entire rocker arm assembly from a '59 to '62. It will bolt right up, so you can't tell without inspecting one of the rocker arms.
If you have a '59-'62 assembly, you can use it but need to use drilled head bolt to replace a specific one of the solid ones. Do a search on this site for more detail.
The '59 to '62 feed tube has a pinched end to feed more oil to the arms. Earlier versions had a return loop to let excess oil flow back to the head. Many owners/mechanics pinched off the return lines of the earlier versions to force more oil to the rocker arms, so I don't think the feed tube is your issue.
Also check to see that the oil holes on the rocker arm shaft are facing down, not up. They sometimes get assembled upside down. Unfortunately, the fit together either direction. Since the shaft is in two sections, there is a chance that your front section only was assembled with the oil holes facing up since 1,2 and 3 aren't getting oil, but the rear section was assembled correctly.
Good luck,
Matt
