Don't use loctite, if the threads are getting ready to pull, the loctite won't help. Based on that bolt turning more than the others on the retorque, I would not trust the hole as is. Here's what I would do if it were me. I'd buy the helicoil kit for that size and a new drill bit for the recommended size. Bolt the head onto the block with the old head gasket. Bolt torque isn't that important, you just want to make sure the head doesn't move. Use the head bolt hole as a guide to drill the hole out to the size needed for the repair. Be careful not to go off center, you don't want to oblong the head bolt hole, it is simply there as a visual to help keep the drill bit straight. If you have an old head that isn't being used, use it. If the heli coil tap will fit through the head bolt hole, you can use the head to visually make sure the tap starts straight. Once it is a few threads in and straight, remove the tap, remove the head and finish threading the hole. At that point, clean the hole out, install the heli coil, on this, you may end up stacking two or getting longer coils and break the tab out of the end. Make sure you don't thread the coil down to the bottom where the threads aren't as deep because when you thread the bolt in, if it goes deep enough it'll catch on the shrunken part of the coil and won't torque properly. You'll want to keep 3-4 threads under the coil to prevent this from happening. It's really quite a simple process and I may have overcomplicated it in my explanation, but this is what I would do if it were mine.