John L -- Hmmm, when we rebuilt my 261, we got oil up to the rocker shafts with just the "Old Distributor Shaft"/busted screw driver oil priming tool (no distributor housing).
Here's photographic evidence! -- Jerry oil priming my 261 with just the oil priming tool.
More evidence! -- Oil actually dripping from the rocker shaft
Chris -- Remember, it's not fully primed until you see oil dripping from the rocker arm shafts, so don't quit as soon as the drill rips out of your hands. Grab it again and keep going -- but not enough to wash the assembly lube off everything
(Jerry told me that -- I'm not smart enough to know that on my own
))
