Just another thought, but the rocker shafts go on one way. there is a notch on them. My memory may be foggy so double check this. I think the drivers side (Left)rocker shaft notch goes to the front and the passenger side (Right) rocker shaft notch goes to the rear. I believe the oil come up to the shaft trough one of the rocker shaft pedestals and if the shafts are on backwards it may not get oil. Like I said read up on it because I am going by memory here and well you know how memory goes...