I started to do an engine swap today. I bought a '53 235 to put into my '46 6400. Everything was going smoothly until I realized that the bell housing on the engine is different from what I need. I pulled the bell housing off my dead 235 and that went well. When I went to pull the bell housing off the replacement engine, I couldn't get one of the flywheel bolts out. I tried a breaker bar and an impact wrench with no results. The bolt head is starting to round off and I don't want to break it.
Any suggestions for what to try next?