Hi Pushkins!
Thanks for the information. My plan is to cut about a 5" rectangle hole across the top of the entire wall. (Thus the hole for each cavity will be about 5" with the width being stud-to stud.) I figure I can cut it out in one piece and then patch it with the same piece. (If it breaks into smalller sections it will still be easy to use as the patch.) Yes, I willl be careful to adjust the saw blade so I don't cut the studs.
(That would kinda ruin my day!) That should take care of any potential pressure issues and give me plenty of visibility. That should do it, eh? Thanks