[pontiacman63383]

So ive got a 69 lemans that was a non-ac car that im installing the factory ac system in and have a few questions. Ive got a few templates for cutting the firewall but still have a few questions. On the underdash box, there two holes and the top and bottom that have holes but no bolts. From the looks of it these holes would be inside of the firewall case so i cant imagine there should be bolts there. Maybe some kind of alignment pins? Anyone know what the holes are for? ( see the attached pic. Holes are circled.) Second question is can someone take a measurement before the top of the firewall box and the lip of the cowl so i know if my marks put the box in the right place (see the other attached pic of when i need the measurement. ) thanks for your help guys!