hi i was an trying to find out if its possible to tell the difference between 2v and 4v heads on a 351 cleavland without pulling things apart first

Google 4V cleveland head ID for pictures. You will be looking for the 4 or 4-dot in the corner of the head. This is not definitive ID as I often grind off the 4V designation, and even if present it does not tell you exactly what 4V head is on the engine - there are 5 different types