shackle hits unibody

Just got back from tellico and after I would go over a water bar, the rear would squat down and the shackles would bottom out by hitting the rear of the unibody. BTW: I have a 96 xj with rusty's 4.5" lift and 32's. My question is will a slightly longer shackle solve this? I am wanting to up my tires to 33's and I was thinking of adding a coil spacer and slightly longer shackles to make this happen. Thanks

What you probably need is a boomerang shackle. Has a bend in it to clear the bodywork.

JKS makes said boomerang shackle, in case you were wondering.