I have to agree with Denny. GM put those things there for a purpose - to keep muck off critical components. However, Ol' Red's days of hauling loads in the rain on dirt roads are long over, she's seen the last of dirty work and might only get caught in the rain by surprise.
So, the splash pans are going... but I didn't just cut the brackets, I drilled out the rivets holding the brackets to the frame. I've got my hands full as it is, no sense making more work for myself.