senor honda

LX/LC springs (just the springs) are all forwards and backwards compatible, issue is what spring rate. Early (05-08ish) had a softer spring in the back with the nivomats; when the nivomats went away through 2010 they increased the spring rate and paired it with an SRT spec Bilstein. Spring rates also vary between the Charger/Magnum, 300 and Challenger. Generally on an R/T, SRT springs will drop you about an inch, maybe a tad more in the back without nivomats. You need to find out of your rear part number is supposed to go with nivomat; if it's an 06 spring then it will.
This is a spring rate break down for the earlier models:
The R/T Charger uses 204 lb/in front and and 514 lb/in rear with Nivomat rear shock.
The R/T Challenger uses 224 front 514 rear with Nivomat rear shock, 547 rear without nivomat.
The 300C SRT8 uses 227f, 622r.
300C 227F / 778R
The Charger and Magnum SRT8 use 284f, 778r.
The Challenger SRT8 uses 261f, 669r.
SRT8s sit 1/2" lower than the 5.7L and 3.5L rwd cars.
The cop car springs are 250f, 652 rear (with Nivomat), but sit even taller than base car due to how they are typically loaded down.