This thread is not dead and here is a short update over the last 2 months.
Found out today after removing third row for some room to haul something that the Bel-tech springs in the rear suck and is what is making my ride rough. It is in turn making the front compensate for the rear. When driving today, loaded down (not a lot, but had more weight) my Tahoe drove really nice for the roads i choose. Not jarring or bouncy or anything. A little stiff, but that is due to the shock settings, but still rode pretty darn good and got me thinking of switching the rear to tony's springs, since they are not progressive rating.
But now another factor is coming into to play and will speak on it when it happens.
Otherwise - all is still good with the coil over conversion. Still like it, still needs some fine tuning - (time has not been on my side) still rides good - especially now that i found out about the rear, and not mad that i changed.
For whomever still reads this-