Unfortunately, no, it is completely manual.

If I were to get a Gear Vendors OD it would only be to have a 5th gear (overdrive after 4th runs out of steam). Even then, you would have to engage it manually with a switch. It would be a total PITA to use it on a daily basis in between all of the other gears.

For my purposes it would be fine. I would give me all the strength I would need (i.e. Level 5 4L80E + GV OD, which is good to 1200 or 1500 HP/TQ I believe), and an extra gear so I could dive down into a lower rear-end gear like 4.10's or 4.56's.

That way, I could get neck-snapping TQ off the line without having to resort to a loose TC, and still get optimum cruising RPM/mileage at speed. I did the math once and with my tire combo, 4.56's, a 4L80E, and GV OD unit, came up with 1800 RPM at 75 mph. That's the sweet spot for mileage.

 

The Gear Vendor unit is nice except for the fact that it's $3500! I'm almost positive they have a stand alone controller that makes it fully automatic now. I looked into it but they don't have a unit that works with the AWD.

 

4.56's with an 80e still is less torque off the line than the 60e with the 4.10s

I wouldn't swap the 80e for a 6l80e. The 80e is a stronger trans and is proven for performance.

 

Gear Vendors has a fully integrated ECU that interfaces with the stock computer.

 

Well, that's cool. When did they implement this? The last time I spoke with them there was no interface.

 

US Gear has a cheaper version of a OD, but you have to set it before you get above 30mph.

It works fine for just towing or whatever, but lacks some of the coolness of GV's.