Yes, but the heat will expand the bolt, more than the hole in the crank, making it tighter. While making the bolt weaker. When I've most often used the torch method successfully, it's when heating the "nut" side of things. In this situation, the nut expands more than the bolt, making a looser fit.
Not identical to this situation - I have found that especially when dealing with steel bolts in an aluminum block, getting the engine up to normal operating temperature before trying to loosen the bolts helps a LOT. I've gotten many out that would have snapped if attempted at room temperature. If the engine can run, that's the quickest way, but a few times, I used a space heater and a heat gun, while watching a thermometer in contact with the area near the bolt.