Ahh, the lift means that now the diff pinion seal/bearing end/uni joint hits on the drag link for the steering!! I can only think of 2 ways to fix it:
1). lower the front an inch or two using shorter coils so that it doesn't let the diff pinion/drag link hit together anymore; or
2). get a custom drag link made up that has a bend in it so that it will clear the diff pinion thru the full range of the steering travel.
But thinking about it a bit more, the relationship between the drag link, which connects both steering knuckles together, and the diff housing shouldn't have changed significantly just because you put longer shocks and coils in there. The leading arms should be holding the diff housing & therefore the pinion bearing in the same relative position, only at a greater angle to the chassis, and the steering knuckles are meant to be mounted solidly on the diff/axle housing too. Something else has gotta be wrong for that relationship to have changed, it shouldn't even vary as the pinion angle is increased by the lift - you are hitting closer to the diff than the driveshaft!! So maybe you need to check the bushes in the leading arms, where they bolt to the diff, and make sure that they aren't shot; and check the steering knuckles and king pin/trunnion bearings too, cos if either those leading arm bushes or the king pin bearings are worn/moving significantly the relationship between the drag link and the diff pinion will have changed so that the drag link can actually hit!!
One of the hassles of lifting vehicles, you've gotta make sure that the steering doesn't foul, and atm, your vehicle is a serious safety risk if you ever drive it on the road!! It could cause an accident, and that could mean you get held culpable for any injuries you cause - better not drive it until you get it sorted!

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