
Like I said, me and
@Dragos80 disagree on overdrives.
But at .586 for a 760 I would want to delete that gear from the controller. I'm sure it can be done. So turning the 760 into a 750 via controller.
Totally unnecessary, the A750 from 100 would be a bolt in, A760 would likely need tail pieces swapped from a TLC A750. (HOWEVER I am still suspicious that the 6th gear is a software change as it is on Allison 1000 and Jeep 5RF45.)
@Dragos80 is looking at OD from the perspective of not gearing with 33s and I am looking at it with axle regear and a boosted 1FZ.
I live a few hours from Moab, I have to get on 80 mph freeway to get anywhere. 2 ODs are great for western freeways AND to give more flexibility in low range, especially with extra deep low range gears. (Its super annoying to be stuck in a group with a Jeep Rubicon or whatever that only has super snail low and takes forever getting between obstacles.)
My current work ride is a 4x4 Tahoe with 5.3, 6L80, 31” ATs, and 3.42 axle gears. The combination works wonderfully.
The 6L80 and 6L90 do NOT have 1:1 direct, but 1.15:1 making the axle ratio 3.93 when converted to 1:1. The ratio spread and steps of A760F are almost identical to 6L80.
I also have a 200 on 34s” and still on the factory 3.9 gears. That needs geared down! Word is that 4.88s are perfect. Tundras, which share the 5.7 and 6 speed transmission with the 200, come with 4.30 gears on their tow package. Scaling that up to 34” is 4.72, closest step is 4.88.
What I would hope to achieve most by 5 speed swap is to find a gear between the A343Fs 2nd (1.53) and 3rd (1:1). The A650 is awfully close at 1.42, hopefully it still makes a difference.