We managed to make piping on a friend's car without removing the AC. Just running the alternator as low as possible, and squeezing between there with a tube worked ok. The alternator sat against the underside of the hose on the TB, and the pipe sat about a finger thickness from the hood.
The tape is holding together the sections that are to be welded. They moved slightly when welded, and we had to make a slight clearance in the hood skeleton, but it still fits and works well.