I just went through this whole thing. Had to shorten the driveshaft a little, and 4.10 is the highest road speed option, but I am completely satisfied with the results.
Before: 5.14 final. 45mph = fastest sustainable cruise. Comfortable road speed was 35 - 40 mph.
After: 4.10 final. Relaxed and comfortable at 50 - 55 mph, fastest sustainable = somewhere over 60 mph.
BIIIIIG difference! This was a farm truck, now it's a road truck.
