I recently rebuilt a 1977 SBC, new items of note are moderate Comp cam, sealed power lifters, timing set, push rods, and roller tipped rocker and a new Edelbrock intake. Heads and valves were done and springs added to match the cam. Primed the engine with the right tool, got 40 psi at in car gauge. I have cold zero lashed the valves, started engine and ran it to break in the cam, pulled the valve covers to set valves closer and noticed very little oil flowing out of the push rods. What would cause this? There is some oil, but not what I would call enough. I can not see any noticeable oil flowing at idle. Is there a welch plug missing or some kind of blockage? I could see oil flowing in the holes in the valley near the distributor when I primed it without the intake manifold installed. I do not see any leakage any where. I am stumped.