you are saying that all 5 qts of oil are on top of the heads?......nothing is draining back....BS.....327 chevy..>>LOL....does not have the open camshaft valley like a small block dodge...probably the pickup fell out of the oil pump like most 327 do...
Yes, apples and oranges... GM designs from that era did not have the level of flow restrictions to the heads that the SBM does. The 4 bangers were really prone to over-pumping the oil into the heads with excess pressure... ask me how I know!