I'm going to put blocks in the rear. I know I'm gonna go with a 3" but what I would like to know is, could I add more to it? Say I go with the 3" and later I wanna go higher, could I add another block on top of it? Say maybe a 2" or another 3". Would that be ok? Or would I have to worry about them shifting or wearing on eachother?? BTW It's a 2005 Ram 1500 4.7 2wd quad cab shortbed.