A-Body Heater Box Blower Motor Face Plate Question

While walking through the show field at Carlisle this past weekend, I spent some time looking at orientation of A-Body heater box blower motor face plates. Apparently, the original design had a hole pattern that would allow the faceplate to be installed multiple ways (not poka-yoke design). As shown in the image below, the face plate has a flat edge. There was a point where a friend and I reviewed (4) A-bodies in a row and they all had the flat edge in a different position. Anyone have any history on this? As I'm typing this question, I just thought about checking a service manual as there maybe an image showing the design intent orientation.

I have a 1968 318 fastback Barracuda that had the flat inboard towards the engine. Going to look for how my 340 formula S was. Don’t have a digital picture to look at. Might be able to find a physical picture at home.

I've got photos of a supposedly untouched 71 Duster with the flat spot on the bottom.

I've got photos of a 67 Dart GT I had that was basically virgin other than engine mods, and the flat spot is toward the inside.

I've got photos of a 72 Duster I had that I am pretty sure had never had the heater box out of it, and the flat spot is toward the inside.

It gets better - the illustration in the 1971 Chassis Service Manual doesn't show a flat spot - it's round.

I don't have any documents to prove one way or the other but when asked I say I believe that the flat side should be at the six o'clock position.

It's pretty common to see them in different locations. Mine was flat towards the engine. I think it looks best that way.

The flat usually is on the top as it matches the flat indentation of the firewall, but I've seen them installed in every direction from the factory.

The plate will fit no matter which way the "flat" is facing. That makes me wonder why the "flat" is there to begin with. Could it be that with a flat side, more pieces could be stamped out of a single sheet of steel...saving the company money?

What would a concourse judge want to see ?!?!?

Calling Mr. Rhinodart.

I have 3 original paint 69 340swingers. All mine are in a diff spot. Does that help lol. I know of one other original paint 69 swinger 340 and it does match one of my 3. This is from 1 la built and 3 hamtramck cars fwiw

My 69 + 68 Cuda Flat faces the Engine . Also my Factory 1968 PLYMOUTH Service Manual , Picture on PAGE 0-16 shows the FLAT facing the Engine . Same 0-16 Page in my 1969 Plymouth Service Manual . I'm sure it's in More places in the Service Manual . Ronnie

Flat spot is always on the right while looking at it from the front...

A build book showing pre restoration photos or marks showing orientation. I think Nats OE gold I think is the only thing offered at that level

My GTS at the time of purchase and likely never having the heater out (77,000 original miles or close to that). Confirms Rhino's comment.

If you can document it during removal or restoration that would be the correct way to put it.

I've only seen thousands of A-body's over the last 44 years, judging a good portion of those at national shows. Of course this is Chrysler so anything is possible, but the majority I have seen are just like the one above...

How mine was. I have photos at home of how the car was in 1980 when we got it and paint shadows confirmed when removed.