I jumped a major hurdle I've been scared to tackle for months now. I successfully removed the 3 broken exhaust manifold bolts in my LQ9 tonight!
Like every other used LS truck motor, I was looking at 3 bolts broken below flush.
Everyone seems to universally recommend using a welder to weld on a nut to get the bolts out. I've done very little welding and the only welder I had access to was a 110v flux core Lincoln. A machinist friend convinced me to try a bolt extractor. After about 5 mins of drilling with a special drill/extractor it was clear that wasn't going to work out!
I worked up the cajones to try the welding method and I got all 3 bolts out in about 30 mins. I just welded a big enough booger to grab with some channel locks or vice grips (thanks youtube).
One hack welder, one weak flux core machine, 3 extracted bolts. Only had one bolt that I broke the weld off and had to retry.
Major relief! Now time to tackle the broken oil dipstick I broke off in the block.