Look at the heads in on the part that sticks out from under the valve cover in the front on the intake side for a big "4" cast into them. That designates the 4V heads. If they aren't there, they aren't 4V heads. If they are, they all had 2.19 intake and 1.88 exhaust valves. Anything past about the first half in 1971 had open chamber heads and about 8.5:1 compression. Just guessing, I'd say 325HP and 350LBFT.
