On to the hole drilling! This probably wasn't the best way to do this, but because I was drilling through the backside of the core support, I also had to drill through two pieces of metal, but because my hole bit was short, I wouldn't be able to drill through both pieces without the drill hitting, I used the hole saw I had for the dash to cut out the outer pices (2 1/2").
Once that hole was drilled, I used the divet to center the 1 1/4" hole for the grommet for the A/C lines. The first hole was a little excessive, but I didn't want to buy anymore drill bits. I'm sure the strength of my core support is fine