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  1. #1

    Default Swapping a non AC heater box in my 86?

    Odd question....but....I am getting ready to start a heater core replacement. My 86 very iis a factory ac car, and I am not looking forward to it. Question is....can I swap the heater boxes out and keep the ac dash vents? Just pull out the old ac box, and put in a non AC heater box?

  2. #2


    Not sure if it's that easy, as the firewall is different between the two. But someone with more experience will know for sure.
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  3. #3
    Moderator wraithracing's Avatar
    Join Date
    Jun 2010
    Grand Junction, CO/RR TX


    The firewall is the same for 1986, but the hole location is different between the two boxes. The A/C box uses the large opening for the Evaporator lines and the heater core hoses. The heater only box doesn't use the large opening and the heater core lines are in a slightly different location and go through individual holes in the firewall from what I recall. Can it be done, Yes! You will have to fabricate a cover for the current large opening and possibly the mounting holes to make the switch.

    I am sure you can modify the box to work with the A/C vents, but again that will take some fabrication and modification. Again doable, but how much fabrication I can not say as I have never attempted. In my experience a good quality heater core, using the OEM style restrictor in the heater hose, quality anti-freeze and correct mixture will allow for a long heater core life and most likely never have to replace it again. Much easier and quicker option than all the changes needed to go from A/C box to heater only. Just my .02, your opinion may vary. Good Luck!

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  4. #4
    FEP Senior Member
    Join Date
    Aug 2003
    Villa Park, IL


    And the non A/C boxes are hard to find. If you have one already, that's half the battle, but like Trey said...
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  5. #5
    FEP Power Member
    Join Date
    Nov 2007
    San Mateo, CA


    I believe what Trey was saying, just use the AC version of the heater box. Put a new heater core in and you should be good for a while. A big part of the difficulty is working with the AC lines intact.during the heater core replacement. I would put a black foam pad over the ac line holes from the inside.
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