Yup. I rebuilt (2) Dodge truck heater boxes, ( both of mine are factory original "non AC" that I'm adding AC to, using donor parts off of factory ac equipped junkyard donors).
I used a 3rd factory AC box I had that was missing parts as a "parts donor" and filler material for one of the good ones I ended up with, I cut up the 3rd box that also had a huge hole in it/ besides what it was missing, and used that to fix a crack in one of the good boxes I have. I JB welded a piece of flat heater box case material over a crack from the inside of one of the units that became a "good" unit, crack was in an area that didn't interfere with the movement of any of the doors within the heater box. And won't be seen. I got parts from DMT and the only thing was that what they supply in the just is great they can't/ don't supply the foam on the blend door or the recirc door ("reg AC vs "MAX AC") for which I found some great substitute for by wading thru the huge selection of different foam materials listed in the McMaster Carr catalog. I don't remember now which particular material I went with but they sell it in 12x12 squares and some they have bigger sheets of, or in a roll depending on which foam it is.
