Small block oiling issue

I have a 67 Valiant with the factory 273 still in it. It had the heads redone before I bought it. I decided to adjust the valves & noticed that the passenger side head doesn't seem to be getting much oil if any. I took both rocker assy's off & blew out the oil hole & it barely has any flow which concerns me. When I took the rocker assy's off,the DS shaft poured oil out & the PS haed a few drips. Where would you check the source? It's my daily driver

What do you mean you "blew out the oil hole"? On an LA the cam has to be in exactly the right position for oil to feed the rocker arms and it's a different position from side to side. If you remove the rocker shafts and crank the engine oil should shoot out the oil holes on each side equally but not at exactly the same time since as I stated earlier the cam has to be in the right position for it to feed oil to each bank.

BTW: is this a new car you just got or something that you've had for a long time?