Dual Exhaust Crossmember Modification on 64-66 A-Bodies?

Just be careful and don't do what I did first: I cut the arc a little too deep, welded the patch, then tried to bolt it up. The trans crossmember bottomed out on the chassis when I bolted it up and the bolt holes wouldn't line up. Had to cut my welds and re-do it. Pissed me off to no end!!!