If you can get close enough to look at blocks, the hemi blocks all have g200 on the front of them stamped/etched near the oil sensor hole, and non hemi blocks have R210III marked in that same spot, its a clear fool proof way to tell the difference
Easiest way to tell is the hemi motor has a dull, rough almost sandblasted finish. The non Hemi's have a more smooth and slightly shiny finish. U put a non hemi head on a hemi motor and it is pretty obvious. But as stated above, the markings on the block will tell u. But from a distance look at the finish of the block and head. U can tell if they don't match.