Sorry no pic - On my 71 Satellite to the right of the heater motor hole in the fire wall are 2 holes, actually 3, kinda stacked atop one another - one threaded & two non threaded that go into the pass fender area. What do these go to or what attaches onto them including the threaded one?

Thanks ,Evan

71 sat a/c firewall
the threaded part and female fitting fitting goes to the a/c lines
i don't have a non a/c firewall pic

Apologies, I should of said "on the right side of heater hole .....from the inside"

Thx for the info though.

on a non a/c car
the holes are on the opposite side of the heater motor
2 holes for the heater core and a possible 3rd hole
for the vaccum lines that would be for a heater control valve for the strato vent option.