340 X heads advice

Look at the valve seats. If they are really wide or wide on one side and narrow on the other, buy aluminum. That means they need guides and seats. The guides wear and the valves flop around beatin the seats to death. Guides and seats alone are worth buying new heads for. Being bare, you're already out valves, springs, retainers and valve keepers. That stuff adds up. Me? I wouldn't even go give them a look.