To remove the manifold.. keep in mind the bolts are in steel that is heated whenever you start the motor. They aren't rusty in the head. This isn't an aluminum head, and it's not a ford and they won't break unless you gank on them at an odd angle. I've taken out more exhaust bolts than any of us could count, I use no penetrant, if you want something different..run the motor and heat them up. The crossover to EM might snap if you don't loosen them equally. Spray those with a little pb and you should be fine.
