Losing Exhaust Stud

On my 1000J motor I have now had the #4 top exhaust stud vibrate out for the 3rd time.  Any suggestions for how to get it to hold in there better?  I would think the temperature is too high for red locktite.

What is the thread like? Not normal for the studs to come out if using locking nuts 

How have you installed the stud? Double nut or one of the tools made to install or remove studs?  When you have installed the stud, is its length proud of the head equal to that of the other studs? 

If there is enough thread length between the head and exhaust flange, you could try adding a jam nut tight against the head to lock the stud.   (jam nuts are usually about half the thickness of a standard nut)

My system is considerably different than stock.  Whomever built the headers left the clamp plates about 3/4" from the head so the studs are well over 40mm long rather than the stock 30ish.  I managed to get a longer stud in place with a full size jam nut on it.  I also found some high temperature Locktite good for 300 degree C which would help, but didn't want to risk using it working in the tight quarters, not having a known solution.  When I pull the motor this winter for a re-ring job I'll go about repairing it properly..