Be careful on some of the "advice" given here on moparts. Please consult the factory service manual as to the proper procedure to tighten the rear suspension bolts.

MP HD springs are made in mexico and have quality issues.

You can effectively and safely lower the car by flipping the front spring hanger or better yet buying an adjustable one from Firm Feel. Do not use lowering blocks!

You may have too much spring rate with the xhd springs but that is a technicality at this point as i have no clue how big your wallet is.