Cognito 4-6:thumb:
Non torsion bar, keeps the torsion bars hidden up no show, costs a little more but well worth it.
From what I was told.
The 4" you use your stock keys which you can crank up a little.
The 6" you'd use leveling kit keys, which I had and put the stock ones back in.
I had already installed the Cognito UCA's and pitman and idler arm a couple of years before I finally decided to lift'er.
Other lifts told me I'd have to re-move my UCA's and put the stock ones back on, that wasn't going to happen.
So Cognito was my choice.