8.5" is about what anyone doing this should plan for if they want any kind of good compression travel. I used a swaybar from my donor 3500 box van (14900gvwr) it is stiffer by a long shot than it needs to be, even at 10ft tall I get zero body roll.With this spring and that mount height I think I gained about 8.5" lift up front, after adding a winch behind the bumper and plenty of settling out those new springs.
I mounted the factory ford sway bar to the chevy frame and it works fine, however I have had one link removed almost the entire time. I just don't feel like it needs it honestly, which I was very surprised to have be the case. It really just doesn't body roll or sway much at all even without it.