Everyone should check this out. Sometimes small town shops are the way to go. This guy is the owner of Kral Auto Parts and he knows how to make a permanent fix. KAP exhaust manifold bolt repair kits are the way to go if you have broken bolts in your exhaust manifold... I wouldn't do it any other way.
https://www.youtube.com/watch?v=qiRHyCuSOGI
https://www.youtube.com/watch?v=d7Px1YindBw
https://www.youtube.com/watch?v=qiRHyCuSOGI
https://www.youtube.com/watch?v=d7Px1YindBw