BE EXTRA CAREFUL IF YOU'RE GOING TO USE A CONDUIT PUNCH!
I used a 1-1/4" conduit punch which resulted in a 1-7/8" hole. That why I am all welded, now.
w00t!
Another "blue taper", here. I use numbers, in sharpie, on my bottle caps and keep a blue tape record right on the fridge. Kegs/carboys get blue tape, too.