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.