What about your head gasket,there is a hole for oil to flow to the top end if installed wrong it can be block off. Pull the shaft and see if you can push a small wire through the head and down if it stops just after the head there is your problem.
i have runned a wire down the hole all the way in to the cam. so nothing seems to be stuck in the hole. i don´t want it but i think the machineshop installed the bearings wrong.
