Lower my 6" RC lifted 1500 to a 4" kit???

[EvilTwin v2]

My truck had a 6" RC lift on it when I bought it. I'm currently running 35x12.50 AT3's on Moto Metal 20x10 wheels.
I've never really cared for the look with 35's (I, personally, think 35's look like a better fit with a 3 or 4" kit). The question I have is, do I need to replace the entire kit to lower it 2-3", or can I simply get a set of coil-overs, adjust them down, and then get it aligned or is that going to screw up driveline angles and suspension geometry?

I'm not looking to half ass this just to save a few dollars, but I'd rather be smart about spending my money, and if I can improve things at the same time, I'd rather go that route.

 

[6.7CumminsDrvr]

Not sure on how big the RC top spacer is but I’m betting there is an additional spacer placed “in” the coil assembly to achieve the full 6”. I’d remove that and see whatcha got, it should be 4”-4.5” if I had to guess.

 

[808ram1500]

RC 6" lift only has a top strut spacer. I have one. I would contact RC to see if the sell just parts to convert 6"-4". Suspensin spacers, rear drop bracket and drive shaft spacer probably. Sounds more of a hassle to me though. Just keep the 6.