so im looking at my options, looks like 55d springs are no longer being made, so anyone have experience with lowering the rear 1/2" with roush springs?
So i just recently had this same debate with myself, I was looking for just a rear spring to level the car because the rear is so jacked up on my stock track pack springs. Anyway I went ahead and did the Roush rear springs only which I saw advertised from anywhere between .5-1". I would have to say they dropped it more than a half inch honestly (closer to an inch most likely). They definitely helped the rear look less jacked up but I almost felt it made the rear too low compared to the front so now it was uneven the other way haha I couldnt win. Anyway I decide to just change everything out for the eibach pro kit as it was one of the least aggressive lowering springs and it was one of the few that leveled the car as the rear drop was greater than the fronts (1" front and 1.5" rear) I am now happy with the stance, the front is lower than I expected it to be honestly but still has a lot of clearance and the rear isnt too much lower than where it was with the Roush springs which makes me think they were closer to a 1" drop anyway. The Rear still sits higher but doesnt look like a 4x4 anymore so im happy with it as its a muscle car anyway so thats how it should be.
Here is a link to the exact ones I bought https://www.summitracing.com/parts/rsp-401295
as far as i could find these were the only option, progressive and not sure about the spring rate as I honestly could care less about it either way.