You might consider using a strop rather than a metal bail. We converted to strops (a heavy webbing loop that goes around the boom, held in place by small clips) a long time ago and have found then to be superior. The cost is very low, they don't require bolts through the boom, and they don't put point loads on the boom.
supplied one made from spectra webbing for the clew fitting on the mainsail
, but I have made all the others from 2 inch wide "seat belt" webbing, commonly available from chandlers. I use three layers and hand stitch them together at the overlap using heavy sail twine. They last a few years in the tropical sun and are easy to replace in situ.