Need a measurement please...

[DLW]

The PO smoothed out my firewall and I want to get my Vintage air unit fit checked. I don't know exactly where to start cutting the holes needed at but I think if I can get the measurement of this one hole in the pic circled in blue I can figure the rest out based on the template Vintage air gives you. I have no inner fenders or anything on the front end right now, so if someone would be so kind to get this measurement and a good spot to reference it from I would be most grateful.