I made the same cut on my bracket, but then I welded a piece from the bracket so I could bolt it to the third hole on the header flange. I actually used the round rod with the holes on each end from the smog pump. I bolted it to the third hole on the header and tacked it where it hit the A/C bracket, removed it and finished the weld.
I used the original studs from the exhaust manifold with some spacers.