Strut replacement question

I purchased my 2007 Ltz 4x4 about a year ago. When I got it, the front strut seals were blown. I replaced them with ACDelco struts with the Autoride and threw on the 2" rough country leveling blocks. I haven't replaced the rear struts yet. Now when I go over speed bumps, the front snaps back down violently. Any idea why this would be happening?

My 2012 seems to do the same thing. I'm sure the struts are from the factory, I bought it with 24,000 miles on it. Hopefully someone with more knowledge will chime in!

The spacers take away from travel. Your upper control arms are probally sitting real close to bump stops, I?m having the same issue hoping some rough country UCA will fix my problem.

Haha two year old thred, go ME