I am the master of weird problems.

Real SS springs normally raise the car. The rear shackles should lslant a little forward but not enough to hit the rear.

The front segment on all A-body springs is 20" from front spring eye centerline to the locating pin where the u-bolts mount. I'm pretty sure all SS springs have the same front CL distance of 20". IIRC, when SS springs are used in a B or E body the front mount must be longer for those cars to make up the difference. It's also possible that your springs are not genuine Mopar but an aftermarket copy made a little differently.

Maybe they are Mopar Oval Track springs that have a 20-1/2" front segment. They come in 1" and 0" arch part numbers.

Everything above is based on my memory but I'm pretty sure it's correct.