lowering shackles to lower 4" lifted springs??

[aggiedave98]

Well, I found out why my '89 suburban rear end is up too high after my 3" fabtech up front and 2" lifted springs in the rear----

it was a 4" lifted spring in the rear!!!

Now, I can either get the shop to get me the correct 2" springs or I can put on 2" lowering shackles that I already have on the way from a guy on the board.

What is the downside of going with the lowering shackles on 4" springs? Any upside??