Guys, you explain all clearly, I too think approximately so...
But I have absolutely other conditions. The duty for import to Russia E350 5.4 makes almost 40000USD. Sorry, I not Russian oligarch...
Therefore I can't choose, what alteration to buy - from Quigley or from Quadravan, ets... The Big good luck became that I have found the Quigley 1997, it very much rare occurence...
I have this Guigley with low T-case and I think - as it to make more interestingly. I listen to your opinions, it is very useful, thanks. While I hear variants: replacement T-case on Atlas or replacement rear shaft.
While I operate according to plan. I use body-lift 2.5"and I will lift AT on 2". And I will look - what problems have appeared. If I receive vibration, I will solve it.
As to safety - in Russia in general to live dangerously. Even if at you isn't present van 4x4.