someone gutted out the heat on car. some questions.. need help

my 340-4 speed has been stripped completly of the wiper system and heat system.

i have all the stuff to reinstall, but i would like to just block all the heat stuff off.

what do i do to block off the big round holes under the dash where the vents came through? i beleive that these two hole go to the vent that is on the outside of the car. i guess you caould call them gills, right near the end of the hood.?

The fresh air vents get their air from the cowl panel. If you don`t want to use the heater box you could simply cut some circles from sheet metal, silicone the edges, and using self-tapping sheet metal screws, attach them to the openings.