ac-vs- heater

[grizz]

bought another 1972 4 wheel drive to help out on the farm going in and out of the fields. this truck had ac in it but everything under dash is either broke or missing. come winter it gets pretty cold here and would like to know what i could do to get a quick fix. would a non-ac dash unit bolt in place of the ac mess i got under the dash. i like this truck so much i might use it as a daily driver,but i need the defrost to work also please help.thank you. no farms no food. tom