[FnLow69]

well if your building a full frame you dont have to drop the frame horn, you just have to make sue that the fenders line up with the cab.

In a nut shell Z'ing the frame raises the crossmember and makes the frame the lowest part of the suspension. because the control arms hit the ground first on our trucks. the reason you drop the horns is so that everything lines up again. If there any thing i can help you with PM me and ill help you if i can.
justin