I have a 6..What year

It has electronic ignition and a '73-up intake. Looks like '70-73 air cleaner and a '74 and earlier head with no smog pump. The year code on the block should be visible in your 1st photo. It would be stamped on the block between the alternator bracket and the valve cover on that small ledge that bulges out.....unless it's been milled off.