Yeah its a persistent problem. The solution I came up with was to clean the bolts (using longer bolts) and header threads with acetone and use blue loctite and put nylock nuts on the longer bolts that stick through the header. Once everything is slimy in the threads, loctite is useless and it will just let go within minutes and they did a poor job of locking the header from the factory.
Its been years since I've had a firestorm now, wish I had one again. I do have an os .18 CV-R to put in one.