Im kinda leaning more towards one of those 200-4r’s now that overdrive is neat. But still i got a ways to think about it.
I'm a big fan of the 2004r. Even with a 3.42 or even a 3.70 in the 8.5(plenty stout) you get a 2.76 first gear and the over drive. It will be more money to build one for 600hp but it isn't out of the question.
Indeed, with the 2.76 first gear and 3.73 gears, it is like launching with 4.10 gears and cruising with 2.73.
Owning a 4-speed myself, I would recommend a 3.08, 3.23 or 3.31 rear gear with an Autogear M23Z (or M22Z if you are under 600 hp) 4-speed. It has a 2.99 first gear ratio.