I had leaf separation on trucks but not cars and leaf mis-alignment on trucks too. Now the big difference was on the trucks I saw it, the axle was below the leaf spring. You have axle over spring. . As the spring loads and unloads you get each slatted spring sliding as it flattens and then curves. You need to track the movement. white shaker inking pen is what you need. With the car in the air and shocks fully extended, note each slat position by marking it's reference on the longer slat above. Now, do the same loaded. To do that- jackstands all the way up at the frame rails by the front of the leaf spring perch and a floor jack to push the rear up under the car. You may need to reference the car on the ground to see where the weight puts the wheel. Once you get where the car is going to sit loaded, mark your slat locations. After, check how much movement between your marks. You need to see front slat movement and back slat movement. If you get a large amount of movement more than 2 inches on your marks, I recommend getting the rectangular clamps that hold the spring pack together - 2 slats per clamp. It may still have a ride with squeaks of metal noise, but nothing more than that. Leaf spring movement is normal and folks run with worn springs and spring helper stuff all the time. It is safe as long as the u bolts are new and torqued right. If you car is sitting higher than stock, it won't handle as good as you will get more flexing. Something I live with.If you can get an AHB rear swaybar and shock plate, you will get back some stability. Take a few test runs and put a passenger in the back seat to enjoy the ride and note and sway.
