Can a B crank be used in an A engine?

[29FordRoadster]

I currently have an A engine with the modern seal in the rear main. The slinger has been ground down to accept the modern seal. It leaks really bad. I have access to a "B" crank and wonder if it can be ground down so as to be used in an A engine. If so, can anyone tell me just what needs to be done for this to work? Any help would be appreciated. Wayne