Infamous 45-55mph vibrate

I've tried searching and got no luck with what im looking for exactly. I have a 2015 dcsb Off road edition, it's got 5100s on all 4 corners, ome 885s up front with the billies set at 0 and 1.5" wheelers aal in the rear... and I've got the damn 45-55 mph slight vibrate. I've tried a couple things already to fix it like double checking all the bolt torque specs, and making sure each tire was properly inflated. I also have an ome carrier bearing drop kit in, I don't have shims yet but my axle looks perfectly straight. Any suggestions? If anyone else has this set up and could chime in, I would appreciate it. I still have a couple more things to try before I'm at a total loss. I was going to remove the cb drop, and see if that helped, as well as rotate my tires and 2* shims would be a last resort. I just didn't think I would need any drops or shims if I kept it under 3" of lift. Thanks for your help in advance. Will post an update if I figure out what it is.