heater box question

The only difference I can see is that the left cable bracket is in a different spot between those two boxes.

The bottom box looks identical to the one I just removed from my '71 Valiant to RnR the blower, but I wouldn't use it. I see at least two holes caused by broken-off cable brackets, and damage along the edges.Also, the box, other than the front panel which unclips, is riveted together so there's not much disassembly you can do.

As long as the studs coming from the blower motor physically match the hole in the firewall of the intended vehicle, it'll fit. That's all that holds them in besides a long "hanger" rod that goes up into the fresh air plenum under the cowl. I hope you have that piece.

You ought to be able to make that leftmost cable bracket work out, just don't go pulling on it much because that fiberglass is brittle.

I have some videos of the box r and r on my youtube channel

www.youtube.com/whosaidtyler