How long did it take you to rebuild your

I'd say that for 4-5 hours to be realistic the box would have to be in pretty good condition. I changed all the seals and gaskets in the box for my Duster, I was probably into it a couple more hours than that but I stripped the blend doors and painted them, had to get a different heater core because the first one didn't fit, etc. But I didn't have to do anything crazy to it, that one was in good shape.

The one I rebuilt for my Challenger definitely took longer than that, probably close to triple that amount of time. But it was kinda rough and I did some fiberglass work on that one to repair a couple corners. Had to soak the rusty blend doors in evaporust for awhile too and then wire wheel them, etc. But I didn't keep track and it wasn't done all at once, few hours here, few hours there, etc.