I am having a problem with one of my Carter's. I can not get the Large brass plug on the bottom unsrewed from the iron body. I have started to tear up the plug a little and don't want to go any further till I have a better idea on how to get the thing out. I don't want to tear it up at all if possible.

I have soaked it in carb dip. Tried heating the cast iron body. I am now soaking the plug with PB every chance I see it dry. Maybe that will do the trick? (I've been using the PB in the previous attempts, now I've soaking it every minute)

I haven't had this problem with the other Carter W1's I've taken apart. Does anyone know a good way to take out a brass screw/plug from a cast iron body?

58' 3200 235 3-speed/OD