It actually happened a long time ago when I first put my header on, it doesn't hurt anything that I know of, except maybe leaks exhaust gases out, but when I was breaking free the bolts on my stock manifold, the one on the very corner broke off half way. How would I go about fixing this? Would some kind of shop drill it out, and re-tap the hole for use with a stock bolt? Or what?

Thanks guys.

 

Potentially, you could burn a valve.

Just got get the proper size screw extractor and nice new drill bit at any hardware store. You'll have it out in a minutes.