Here is a shot of the dashbar taken through the glovebox opening. I can measure the distance of it to the firewall if you have some A/C unit dimensions, I am interested in A/C eventually myself.
Thanks for the pic, in research phase of AC/heat systems now. Really mostly to get windshield to defog properly and AC would probably be nice on drag week. I remember going late rounds in the roadrunner at night and windshield would fog if big drop in temp like that year at Norwalk running till wee hours.