i have the exact same issue. it started as soon as I installed the lift. I have the oem double cardan driveshaft. I tried taking it off and driving. The symptons were still there but much less noticable. this leads me to believe that the issue must not be driveshaft related (at least not completely) but more likely having the driveshaft attached just exaggerates the vibrations. so in that case the issue seems to be either axle or transfer case related. like you it definately sems to be coming from the front. I have already changed both hubs due to another issue and that changed nothing. im now leaning toward a pinion issue. im definately no expert. thats just my train of thought. start with your driveshaft since it is a common problem spot. keep us updated if you solve it.
2002 WJ Limited [B]4.7[/B]: 6" Clayton REALLY long arms....yep, they are longer than yours [B]SOLD : ([/B]
1998 Platinum [B]5.9[/B] DD
2007 WK Overland [B]5.7[/B] wifes DD
[B]"In a world that he did not create, but he will go through it as if it is his own creation. Half man, half beast, whatever it is it is weird, it is ticked off and it calls itself Slash"[/B]