I need to install a bail on my mast for vang attachment, I would like to thru bolt it as opposed to screwing or riveting, , can anyone who has done this tell me whether I need to remove the mast base, wondering about wires I might hit when drilling thru, also if some one has done this, what size bail and bolt , did u use, any suggestions for drilling to assure a perfect 90 degree penetration so I come out lined up in line with where I start drilling, the mast is z spar , thanks as usual for all of the help.