Some Fords were built with the nose higher than the back. The Mustang is one example. They gave it a stance that "made it look like it was moving while sitting still". That or maybe the rear leafs need replaced. Hope this helps you.

My first car was a 54 Ford with virtually the same rear spring set up.When the rear end dropped to low I flipped the spring shackles causing the rear end of the car to level up with the front. The down side to this was the car had too high a center of gravity creating a spongy feeling to the ride. The same feeling you get when riding in a horse drawn carriage. Replace everything new (springs, shocks, front bushings, idler and tie rod ends and ball joints) to factory specs and you should be ok.

I have seen in the past where people have fliped the springs, it will raise the car some not alot tho. I do not know how it would effect the ride or handle on the rear of the car.

The Crowns always looked better in that position. I have a Crown. Check your rear springs I would think either replace them or I had mine re arched and a small leaf added in. It will look high but will settle down about 1 " . Or you could make lowering block but put them in the opposite way which will raise the rear end. You have not said how it rides. If the rear bottoms out you need new springs. Best not to play with the front end. Last you could add gas schock to the rear.