Leaking from head bolts

I have 73 340 and it has started dripping coolant from the 2nd header bolt from the front on the drivers side, will sealant work or do I have a bigger problem. Car has not ran hot last trip the temperature stayed at 170 and I noticed the leak then.
Any help or suggestions would be greatly appreciated. Thanks
I used Permatex thread sealant with PTFE and haven’t had anymore leaking