New to me 05 DC 4x4

Nah. If you hang out a little bit around here you'll see the AC vs DC pop up a few times. It's all in jest. Mostly. Well, not really. But you get the point.

 

I’d like to see an LT4 swapped into a nice FGT.

 

its all fun and games until someone brings up sawzalls and tube bumpers

 

So to answer the actual questions Deflated airbags shouldn't affect ride height, but may minimally. There is a minimum psi so they don't get damaged. The rear suspension looks stock other than the shocks.

You can lower it with shackles. I forget the details, but something about our shackles is backwards, meaning lift shackles will actually lower it.

 

As long as elevator guy doesn't see it...