3" lift led to vibrations and howling???

After installing my 3" kit, as expected I noticed some vibrations between 30 & 45 mph upon acceleration. I have ordered the Skyjacker transfer case shim kit to combat the issue. Anyone had great success with this as a remedy? Also, a howeling sound appears within the rear section of the driveline upon deceleration at almost all speeds, I suspect a U-Joint??? This part I really need some assistance with. By the way, the 2001 Limited has 45K miles on it and is a 4-door version.
Thanks again,
MAC

Year model...I have an 01 and had both DS replaced...also has the vibes and longer LCAs with Poly bushing have cured my vibes and DW.