I have a '47 that I just put springs,valves, and guides into. Everything is great, but I am getting oil misting out of the rear exhaust spring cup, and getting all over the seatpost down tube. The push rods are well sealed,(no leaks). I have checked the return line from the spring cup to the head, and it is clear of obstructions, and the line is sealed tighly to the nipple. There are no cracks in the flair at the nipple, and no leaks in the line. When putting it back together, I noticed that I have 2 different types of pushrods. The exhaust have like a bronze ring around the lower portion of the pushrod. The other ones(intakes) do not have this bronze ring. Could this affect the vacuum on the exhaust side?
It did not leak before I did this headwork. Any ideas as to what could be causing my leak?