[PC/SR]

Just an FYI on yet another stud removal problem, a new one for me. Bought a block, could not turn any of the studs out, in fact broke one. Followed the usual procedure and soaked with acetone/ATF for about a week, no luck. Applied 0x/acetilene heat, red hot, hit with hammer, let completely cool, no luck.
Next time, heated red hot again and applied the pipe wrench before the stud cooled too much, about a minute. Broke free and came out.
Found carbon, not rust on the stud. I surmise some prior builder put Permatex 1 or 2 on the stud and over time it just became a hard glue and the heat loosened it up. Good news is no rust and the threads are really pristine. Have never seen better threads on a old block.

In the usual situation (rust) you want to heat the stud and let it cool to get some miniscule separation between the rust and block and stud. Here you want to melt the Permatex and keep it hot and pliable.

Caution, do not try to turn the bolt while red hot, let it cool for a minute or so. I broke one off applying force before the tensile strength of the bolt returned, it was too soft until it cooled a bit and hardened. As I say, about a minute worked for me, the stud was still plenty hot, but hard again, and the Permatex loosened. The longer you keep the stud hot the better for "melting" the Permatex.