Panhard bar.
If I were you, I wouldn't bother with that flimsy factory POS....buy some boxed control arms and adjustable panhard bar (you can center your axle back where it's supposed to, it's no doubt off center since you lowered it). Those 2 rear suspension parts make a world of difference launching and just generally helps put down the HP much better, even in the turns; no axle hop! Those parts don't cost much and are well worth it.
The stamped steel bar is quite flimsy. if its bent or looks warped chuck it and buy an adjustable one in case you ever want to run bigger 11" wide rims. You'll need to properly center your rear end.
EDIT: nice work BTW with the rear end carnage. Share some picks!
+1 for the pics






