I run dual T-cases now in my toyota. My issue is this is for my flatfender. Even with pushing the rear axle backwards about 8", I'm not sure how much drivetrain length I'll have.
If it'll fit, I'll drop my entire Toyota driveline in there, just don't know if it will fit.
On my TJ, I rarely if ever used 5th-low, and never used 3rd-low in my CJ. 2nd low in the CJ was 2600 rpm @ 20 mph.
I suppose I could drop in my 4.11s instead of the 4.88s, but thats going to hurt the overall gearing.