For a good sense of how your car was designed to look in real life, I’d rely on the original TV/movie commercials that show the cars
being driven. That takes care of most of the worries about the mind tricks ( perspective etc.) that photographs might play.
This is not a 1969-only phenomenon -- see, as great example, this
commercial of a 1970 SFGT in motion which again shows the front higher than the rear (is that "negative rake"?):
Now, to my eyes, there is one C-body Plymouth that looks to be perfectly level front and rear: the Suburban. Compare the stance of the 1969 wagon in
this ad to those of both 2-doors above:
The "in motion" orientation can have its issues, too, as to whether the car is accelerating or being driven at a steady speed. A car with a slightly higher front end level is supposed to imply "a vehicle in motion, under power" rather than not. Which can also relate to a slightly lower rear body height. Just as in the earlier 1960s when many drag racers would lower the rear suspension heights for allegedly better weight transfer (at the starting line) and traction. It was more about "the look" and perception that the car was fast, even if it was not actively raced.
As I recall from the fsm, there is a range of specs for the front end height. Depending on engine, suspension option, and if it's a station wagon or not. Which can then reflect the number of leaves in the rear springs (and related build heights of the spring assy at its mounting point). Still, to keep the resultant car sitting mechanically level through all of this.
I'm defining "mechanically level" as the vehicle's rocker panel being parallel with the road surface.
On my '67 Newport, I upgraded the y-pipe back exhaust system to that of a '72 440 C-body. It all fit together as desired as the wheelbases are the same, BUT the difference was that the behind-the-axle pipes needed some adjustments upward to clear the existing Class I trailer hitch (which was on the car when I got it). Why?
After I got to looking at our '72 Newport, it was obvious what was going on. On the '67, the rear sheet metal angled UP to the rear bumper height, from the rear wheel area. On the '72, the rear quarter panel was still angled upward, but not nearly as much. Reason? While the rear bumper height was not that different, there was a valence panel UNDER the rear bumper which completed the rear sheet metal of the car. As a result, the rear pipes had to clear that and were more horizontal in their orientation. So I took the car to a local muffler shop, explained what I needed, and the '72 pipe was tweaked to raise it about 1.5" to be just below the '67 rear bumper's lower edge, as was stock. When done, it was "right".
With the rear sheet metal being more horizontal on the Fuselage cars, any little bit of rear spring sag will be more evident. Or spring build height differences, for that matter, which can move the body up or down, as a result of more leaves and resultantly a bit stiffer spring. Which would explain the station wagon appearing more level than the sedans (in the ssles brochure). The wagons would usually have 6.5 leaves and most sedans would be 5.5 leaves, as I recall.
Which can bring up another orientational relationship. IF the rear springs are correct in the number of leaves AND support weight specs, then the front suspension adjustments would need to keep the rocker panel level. Just the opposite of getting the front correct and then assessing the rocker panel orientation for correctness of the rear (now used) springs' condition.
Enjoy!
CBODY67