broken bolts

I have a 4.6. There are 2 on one side and one on the other side. broken exhaust manifold bolts. I got one out which left these. stripped 5 bolt extracters and broke 2 more. What would make these freaking things stuck in the heads. cant be rust. Any ideas on extracion motor is out of car . but they wont budge. Thanks

I assume you've already soaked them down with PB Blaster, or WD40, or similar. I've heard that wax is a wonderful thing. Get a propane torch and heat the bolt and apply wax to the opposite side. The heat should draw the wax into the threaded area very similar to drawing solder into a joint or wire.

Yeah I have sprayed and sprayed them. Any kind of wax?