Heater Box Swap ’73 Swinger

Tech Question

Craig Robertson, Utica, MI, 1975 Dodge Dart Swinger 318 V-8

I am replacing a heater box and controls in my 1975 DodgeDart. The only thing that I can find that is in good shape and not missingpieces is a complete unit with controls from a 1973 Plymouth Duster. My 75system is for a/c, but the a/c is gone. The 73 is not an a/c system. Willthe swap fit or am I going to have issues? Please advise.

Craig, if you have EVERYTHING from the ’73, including the box, core, blower,cables, control / switch, etc., it will work. But you’ll almost certainlyneed to make new holes for the core’s nipples in the firewall. Probably theeasiest way to do this is to bolt up the outer half of the box (empty), andmark the hole-center locations, then drill small holes from the inside, thenhole-saw from the engine side. Pluggin the old core nipple and evap linesholes will be up to you. Correct, of course, would be welding in steelpatches. Sleazy would be tape, be it duct or aluminum foil.

You’ll need to ditch all the A/C ducting, obviously.

Defroster hoses should be the same.

This is a miserable job, but not especially difficult.

Rick