right now i have a 4" lift with drop brackets in the front and block in the rear. my rear leafs were sagging so im going to put ex leafs along with a set of longer shackles. depending on how it sat i was thinking about either putting a spacer in the front or 6" coils, then it dawned on me " do i need longer drop brackets if i put 6" coils up front?" or would my current set up be able to handle that?