I have a 3.5 RC lift on my jeep that only came with front lower non adjustable control arms. I'm planning on probably putting Currie 4" Springs and better shocks. Would control arms be a good idea? I'm debating between Metalcloak and Currie arms... Thoughts?

 

Your front lower arms are longer than stock, which pushed the bottom the housing forward, which lowered the pinion and raised the caster. Adding another 1/2" of height (depending on the specifics between the coils, maybe a full inch?) won't affect the caster a whole lot. If you want to adjust it, add a set of adjustable upper arms to tilt the top of the housing back. And if you want to relocate the entire axle forward in the wheel well, then yes, you will need to add both upper and lower adjustable arms.

For the rear, there is no caster to worry about, just the pinion/driveshaft angles. Assuming you are still running the stock driveshaft, the angles should be ok. If you move to an aftermarket shaft, you may need a set of arms to adjust the pinion angle. Or, if you want to recenter the axle in the wheel well, then you will need two sets.