Willie B

Here is my issue. My exhaust manifold on my 4Runner, is about to friggin' crack in half, it is needing to be replaced. I have another exhaust manifold off of a carburated truck I used to have. It will bold up perfect, but I need to drill a hole and put in studs for the O2 sensor. There is a flat location in the manifold to do this. I am just curiouse if anyone else has sone this, and what size drill bit you used.

Thanks!