In 2007 the G56 had a ratio shift, all 6.7's have the new ratio, rare to find with a 5.9.

Ratio's are
NV5600: 5.63, 3.38, 2.04, 1.39, 1.00, 0.73
G56 (early AD): 6.29, 3.48, 2.10, 1.38, 1.00, 0.79
G56 (late AE): 5.94, 3.28, 1.98, 1.31, 1.00, 0.74

Thanks!!
Excellent info, I had no idea. Just knew I didn't want another nv5600. Always shifed a little tough and shelled out @ 237k. The new (06) truck evidently has the early g56. Hope it lasts longer than the nv5600

 

My 06 has the earlier G, and I like it. With 3.73's I like the ratios a bit better for towing than the NV truck I used to have. MPG's aren't as good as my old 03, though.

 

[QUOTE=toesmack;2749499]In 2007 the G56 had a ratio shift, all 6.7's have the new ratio, rare to find with a 5.9.

Ratio's are
NV5600: 5.63, 3.38, 2.04, 1.39, 1.00, 0.73
G56 (early AD): 6.29, 3.48, 2.10, 1.38, 1.00, 0.79
G56 (late AE): 5.94, 3.28, 1.98, 1.31, 1.00, 0.74

I guess I got the best of both worlds (just about) I have a NV5600 with a gear vendors overdrive behind it. The gear vendors ratio is .78 so when I am in sixth with the GV turned off I have a .73 ratio and when I am in Fifth with the GV in Overdrive I have a .78 ratio and when I am not towing I can by using double over go to a .57 ratio which is great for the 70mph+ freeways. As someone mentioned the NV5600 could use a lower speed reverse gear for backing into tight places. I have ordered dynatrac freespin hubs so that I can use low range for backing up and turning at the same time.
Jim O

 

That is what I want to do also.. But I am thinking the US Gear version, its a .8 OD.

I think the ideal truck would be a truck with 3.42's, and a 7speed manual, 255/80/17's and the following ratios.

1) 6:1
2) 3.5:1
3) 2:1
4) 1.35:1
5) 1:1
6) 0.86:1
7) 0.70:1
R 6.5:1

It would let you be 2K when empty at 80, 2K at 65 when towing, and only 2300 in 5th at 65.. And when towing a small trailer at 75 you could be at 2300 as well... I think it would work well.. but that's just my dream. I like the 3.42's over 3.73's for the extra speed in 5th, the motor makes the tq to pull it, but sometimes I don't want to be spinning 2500+ to run 65.