rear height

[maxb]

the front fender is just over 26" and the rear is 28" ....after taking out 2 leaf springs from each side leaving 5 leafs on one side and 6 leafs on the other, it srtill rides a little high--- I'm going to install these front hangers and hopefully it comes down a little more. there is exactly 1" between the centres of the holes.
I will also lower the front a 1/2 turn or so with the torsion bar. btw --the 2 black front seats are out getting re-done, the single white seat is a temp seat.

 

[Katfish]

Those will probably get you close.
I bought +1" springs when I redid the rear. It was too high like yours, so I moved the leaf to the other spot on the hanger and that did the trick.

 

[HPP]

I suppose you could use a shorter shackle to get a slight amount of drop. Being at the rear of the spring, it isn't a 1:1 drop for the amount you move the leaf up because the springs are asymmetrical. Of course, doing this will put the leaf closer to the frame rail and there will be the possibility of it rubbing or that it hits on dips that could lead to some banging noise.

The two hole mounting brackets are a common way to change height. You also can flip the stock bracket over to create some drop because it is not centered in the bracket. Remember that 1" change in front eye height will not equal exactly a 1" drop at the axle center line again because the springs are asymmetrical. But it will certainly drop it some.

Don't forget that with unequal tire sizes front to rear, you will get some rake in the car. Anything you do to level the car with the different sized tires will need to be easily reversed if you decide to go to equal size tires all around, if you want to retain some rake. However, as I mentioned earlier, most Challengers appeared to sit too low in the rear from the factory with equal height tires because of the way the body lines change behind the rear window. It takes a few degrees of rake to get the trunk lid to sit more level to the ground instead of sloping down.