No oil pressure to the rocker shafts.

What @4spdragtop said is correct; Down and left is correct.and it is the ONLY correct way.
The shafts only get oil when the cam and the holes in the cam bearings line up, which only happens once per revolution. At cranking speed, it takes a long time to fill those tubes up.
So then, if the holes are Not lined up, you can prime the day away and no oil will come up.
I forget the cam position that are requires, but they are different from left to right. I\ll see if I can find that info.

What @toolmanmike said will prove the headgaskets but you still have to line the cam holes up

here it is
from @Rapid Robert in thread; Priming the rebuilt engine question

turn the crank to 90 degrees (1/4 turn) BTDC #1 compression & preoil the pass head with the hex shaft (some dampeners have partial marks (3 of em) in addition the the full TDC timing slit) or if not cut a strip of paper 5.694" to use as a ruler. then turn the dampener back around CCW to 20 deg ATDC # 6 compression & preoil again for the dr head. this will preoil both heads with minimal turning. then turn the crank back CCW a bit more to your preferred initial (IE 15 BTDC) & install the dist with the rotor under where the #6 plug wire is. It'd be a good time to check rotor phasing. and only vac adv not mechanical changes it (shifts it CCW on a SB) from its static position in relation to the cap terminal.