Originally Posted by John E

I have never tried this, but one might be able to cross-thread retap the right side for a right-hand thread. A friend of mine did something similar with ALUMINUM cranks when he built a tandem and needed two drive-side cranks with left-hand threads and one "left" crank with a right-hand thread, and it worked like a champ, but I don't know how well the technique would work with a steel BB shell.