So, would the 3rd member from a 4.7 or 4.6L Tundra be a drop in since they used the 9.5" axle? With the 2016+ 8 speed trucks having a factory 3.31 ratio, the 3.91's from the Tundra 4.6L would be pretty mint with a 35" tire, or even a 37. Even with a 37", they would still be slightly shorter overall than the stock 3.31/32" tire combo.
1st gear would be shorter than the 6 speed trucks with 4.88's, but 8th would still be decently tall for the freeway. I figure it would be at 2000 rpm running at 75mph with a 315/70R17