i think these are usually attached to a large bail mounted on the mast base.

check http://www.ballengerspars.com

:: Last night we were sailing and noticed that the boom
:: vang bracket that was suppose to be attached to the
:: mast, was not.
::
:: The boat has a boom kicker and there is a bracket with
:: two halves that has a plate with three holes for the
:: kicker and the purchase attachments.
::
:: It looks like there were two screws either side to
:: attach the bracket to the mast. The threads are striped.
::
:: My question is has there been a better bracket made for
:: this or I was thinking about having some extension
:: welded on to bring the bracket around the mast more.
::
:: Any thoughts? Thanks for the input