273 Rocker Assembly leaking?

Do you have any stock rockers and push rods? Since you're running a hydraulic cam, if the cam isn't huge, try stock rockers and push rods to see if the leakage goes away. Also, check to see if the shafts are installed upside down. The oil holes in the shaft are supposed to be on the bottom. If they are upside down, the shafts could be filling up with oil and the excess that isn't getting to the rockers is having to find a place to go.
I unfortunately was only left with a set of the adjustable rockers and a set of cheap aftermarket aluminum ones. The aluminum ones are 1.6 ratio and too much for this application. It appeared he was changing to roller hydraulic but it was a nightmare. It appeared the rollers would open up oil gallery at every lift. Also pushrods would be rubbing heads that where already installed. It was put together by a shop here in niagara but very questionable