don't seem to be getting oil up to the rockers. 60psi on gauge on filter. very little seeping from hole in top of rocker. When I shut it down and move rocker over on shaft, oil does come out of the shaft hole. But no way to check if it's under pressure when running. do the rockers have channels to bring oil from shaft up to top of rocker hole? could they be blocked? (hole in rocker shaft is at 3 oclock and whole in rocker top is at 12 oclock). could oil channels through head be blocked by gasket? when running i only get a little seepage from holes on top of rocker. 60psi at the filter. are the shafts side dependent?

1963 GMC Suburban