You mean the rear sway bar? The factory one and I'm sure most of the aftermarket bars have no issue with clearance with the Vogtland drop springs (I have them) but you do need shorter endlinks which I used Energy Suspension universal ones.
I made mine with 2 pieces of plate steel for the sides, and a piece of 1-5/8 roll bar tubing, so I could then jack the rear end up by the brace itself. And on the track, it definitely made a difference! The rear was noticeably more predictable under hard cornering with that brace there.
-91 Cougar LS, coming soon, complete overhaul with a 427" Windsor.
-90 XR7 5-speed black on black w/sunroof, MP2, coated rotors, double intercooler, 15%OD, ported heads, comp stage 1 cam, 85mm TB, 90MM LMAF, 80# injectors, and ported big valve heads
-98 Mark VIII LSC, Procharger P600b, TR3650 swap and 3.73s.
-90 SC Automatic rustbucket winter beater
-97 Tbird Sport 4.6 Nice weather daily driver
-"Your buddy Mike is INSANE!" -ClintD's dad