[SIR]

...there's this stuff called "p-b,blaster" it's an airisol spray you can buy at your parts store spray it on and wait it will take some time so go slow...once it has broken loose move the bolt back and forth to keep from jambing the threads keep spraying it on till you can remove it don't put a flame (torch) near this stuff it WILL BURN!! and if the worst should happen....sh*t can it and go get a good set of headers....no mo problem...good luck.