Pull all spark plugs and pull the coil wire and spin the engine to make sure you do not have oil sitting on top of the pistons, any valve that is open could let oil that was setting on top for just a couple hours will make it's way past any old seal and worn guides..
Was this /6 setting for a long time ? and you started it ? You broke up a bunch of sludge and it plugged up your oil passages, wow, I would like to see the engine with the valve cover off, I bet the push rode are sliding up and down a cake of built up sludge ........................Just a thought.
