Stamped block numbers below head

Think it should be HW(3)60R3694(XXXX)

H = 1972 engine model year
W = Windsor engine assembly plant
360 = cid
R = Regular fuel
3694 = date Wed, September 8, 1971
xxxx number of engine built that day to yours.

Are there letters/numbers midway across the right oil pan rail?

I would say from this information it is a 360 production engine.