Cross Threaded Exhaust Manifold Bolts

Those are header studs. I always pick up a set from Alper Motorsports when doing headers. Thread the studs in, install the gasket, slip on the header, and torque the nuts to 25 ft/lb. Done.
I wouldn't worry about warping the flange. Even the cheapy LS headers have a 3/8" thick flange. One missing bolt isn't going to hurt anything. Obviously, it is better to fix the threads, but if you are making things worse, just leave it out. MLS gaskets and the 3/8" flange will take care of everything.
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And yes, you absolutely must be straight when drilling for a helicoil, but you should be able to salvage what is already there.
The Best V8 Stories One Small Block at Time

Those are header studs. I always pick up a set from Alper Motorsports when doing headers. Thread the studs in, install the gasket, slip on the header, and torque the nuts to 25 ft/lb. Done.
I wouldn't worry about warping the flange. Even the cheapy LS headers have a 3/8" thick flange. One missing bolt isn't going to hurt anything. Obviously, it is better to fix the threads, but if you are making things worse, just leave it out. MLS gaskets and the 3/8" flange will take care of everything.
I want to point out that these are header studs; not head studs.
That way when you go to install the bolt finally, you can hand tight it by feeling it first couple of threads, to ensure it does not strip. You won't strip it with your hand tightening. That only happens when you put a tool on it to force it, and the dirt/filth is what creates the issue given everything else is true.









