what ride are you after,, i have a srt and already installed the front springs from a limited,, a little softer but hard to tell with the srt springs in the rear,,, i am have the rear changed in the next week or so,
I can tell you this the srt springs are .610 dia and the loose height od 14" and 12"
the limited springs are .550 dia and 14" and 13" tall
I also have two springs that are .550 dia and 15" tall ,,i was told they are from a limited also.