Driving around is what rusted them in the first place.
No harm in letting the hardware "marinade" in penetrating oil.
MAP-Pro may or may not get them hot enough to do some good. Keep in mind that some heat may allow the penetrant to soak-in, but heat makes steel weak--you don't want bolt shanks or studs to be hot when you remove them. Nuts can be warm, but not so warm that they distort or round-off.
"I" would heat the nuts 'til they glowed. When they've cooled enough that the penetrant you're spraying on isn't smoking, rattle 'em off with a six-point socket on an impact wrench. Use the shortest extension you can. The less there is between socket and impact, the better. A swivel socket can be a real blessing, as there's no side-force on the stud to break it.
Getting the studs out of the head would be somewhat similar--heat 'em til they glow, let 'em cool so that when you add your penetrant it isn't smoking. Turn 'em out at room temperature, possibly by locking two nuts together and then applying force to the inner nut to back the stud out. Be REALLY CAREFUL if you're applying side-force on the stud or bolt. Side force can cause the shank to break. Avoid side-force if possible.
No harm in letting the hardware "marinade" in penetrating oil.
MAP-Pro may or may not get them hot enough to do some good. Keep in mind that some heat may allow the penetrant to soak-in, but heat makes steel weak--you don't want bolt shanks or studs to be hot when you remove them. Nuts can be warm, but not so warm that they distort or round-off.
"I" would heat the nuts 'til they glowed. When they've cooled enough that the penetrant you're spraying on isn't smoking, rattle 'em off with a six-point socket on an impact wrench. Use the shortest extension you can. The less there is between socket and impact, the better. A swivel socket can be a real blessing, as there's no side-force on the stud to break it.
Getting the studs out of the head would be somewhat similar--heat 'em til they glow, let 'em cool so that when you add your penetrant it isn't smoking. Turn 'em out at room temperature, possibly by locking two nuts together and then applying force to the inner nut to back the stud out. Be REALLY CAREFUL if you're applying side-force on the stud or bolt. Side force can cause the shank to break. Avoid side-force if possible.
