I have an O-320 in a similar situation to you. Stored for about as long after it had been run for 286 hrs since OH. I just plan on doing what one of the famous engine gurus suggested, which is put in fresh oil, pull the plugs and spin the engine on the starter until oil pressure is indicating or prime through one of the gallery plugs until pressure is showing. Re-install the plugs and fire it up. After a ground run/runup, I will do a compression test to see how it looks. Since this engine is on a new 4 I will be staying over the field for the first flight. I have scoped the cylinders and all looks good. Will also do a filter cut after 5-10 hrs.
Just my plan, good luck with yours.