Years ago when these cars were more popular, many of them had the rear springs replaced because the ALC no longer worked, and the rear would sag when loaded. It was a much cheaper option to install springs for a car without ALC, or even the Cargo Coils that were popular at the time.
I also replaced the rear springs on my '75 CDV with these Cargo Coils.
The cars always sat higher on the rear with these springs.
Now, if you replaced with the correct rate springs for a car with ALC, the car will likely sit a bit lower than the factory trim height. Originally these springs were not strong enough to carry the weight of the rear of the car themselves when even there was a full tank of gas. The ALC was to compensate for that. There is a small amount of adjustment available on the level sensor arm to set correct ride height.
So, assuming that the correct rate springs for the car have been installed, and the ALC on the car functions as intended, then you should be able to set the rear ride height by adjusting the level sensor arm if you are within an inch of the correct trim height.
Mike
