Eric,
Those aren't bolts, they should be studs. Did the studs back out or did the nuts unscrew? Locktite will do you no good as the heat generated in this area will burn up the locktite. If the studs are still into the head completely, and the nuts came off, you might consider just converting to all-metal lock-nuts with new lock washers. If you were getting a lot of heat out of the header over a period of time, you may well want to change out your intake/exhaust gasket. If you go this far, may as well place new studs as well. I think these are all 3/8" NSF fine thread. Good luck. Beware that you should use the proper studs, usually only available (or easily available) from most LBC vendors. I get all my stuff like that from TRF. I don't think that ARP Racing has those particular studs or at least they said they didn't when I tried to buy from them.
Bill