It looks like you resolved your gearing issues. With 315s it is like a 3.73 NV5600 with stock tires. The gearing is almost identical. At least with klenger's site excel spreadsheet.

I just don't see an issue with it being a little over 200 RPMs higher. Fuel mileage with the 610 NV5600, and the 610 G56 is about the same. Atleast what I have seen from mileage posts on this site.

 

I like 6th gear just the way it is...because if I wasn't turning those RPM's at 70mph I wouldn't be able to hold my speed going up the hills on the interstate pulling 26k lbs.

 

Agreed. With the power, the gearing is just right. I can't believe all the guys who are ranting about how much they dis-like it?? I don't have a whole lot of miles on mine yet, but I can tell you it is far better than my 01 Auto....

 

I think the g56 is much better than the auto, at least in the towing department. Pulls like a dream. Mileage has never been my issue since mines a dually 4x4, I have yet to hit 17 hand calc'ed. If I wanted a high mileage vehicle, I wouldn't be driving a 8k lb truck.

One other advantage the g56 has over the auto is the ability for the tranny to slow the engine on down grades. I pulled across the smokies and never once had to use the brakes to slow down. Let off the gas and the engine gave just enough braking to slow me down smoothly. (This was pulling a 10k fifth wheel too). sort of like a poor man's jake brake.

Yes a 7th would be nice. But I dont spend much of my time on the interstates so it really doesn't impact me all that much. Just kick back, set the cruise on 70, ahd hope you can reach that high number of 16mpg on the highway!

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