4.5 lift?

i have an 89 xj laredo with a 3.5 inch lift on it right now and im gonna make me some shackles, a transfers case drop, and control arms. my question is will i need to add degree shims to the rear axle or should it be alright with the shackles and t-case drop. also to make 1" lift i need to make the shackles 2" longer right?

thanks
david