I know my truck is a NNBS and not a NBS, but same deal here. I'm running a 3/5 drop on my '07 Burb. I'm also running Eibach sways front and rear, along with DJM end links in the rear and a Spohn adjustable panhard bar. My sway bar contacts the panhard bracket, even after moving the driver side sway bar mounting bracket over one inch. I'm going to see if there's anymore room to move it over more because I need to fix the issue of the sway bar hitting the panhard bracket and I have plenty of room before it would contact the right side shock. I could just put the longer stock rear end links back in, but that'll bring the bar angle back down and I want it parallel to the ground like it should be. If I can't move the driver side sway bar mount over towards the passenger side any more than I already have, I might just end up having to modify the DJM end links so they're a bit longer than they are now, but still short enough to keep the bar as close to parallel with ground as possible.
The best solution is to get the sway bar far enough over to the right that it totally clears the panhard bracket. If not, it'll just end up hitting it again once I do the free travel mod and the rear suspension has more upward travel. So I don't think that lengthening the DJM end links would really solve anything now that I think about it. I'll just have to figure out how to move the sway bar over to the right about another 1/2" so its totally clear of that panhard bracket. That's all it would take in my case because its almost clear as it is now, but not enough so its just barely making contact.