At Next Gen Diesel, we are proud to offer built 10L1000 transmissions for the 6.6L GM DuraMax Silverado/Sierra! The 10L1000 is actually an evolution of the 6R140 from Ford/ZF, used in the previous generation of Super Duty. That's correct! The Allison 10L1000 is a near mirror of the Ford 10R140, with a few proprietary differences to apply to Allison's engineering and currently held patents. Through enhancements in materials used and upgrades to the units hydraulic efficiency, the unit is given great benefit in applications ranging from daily driving and towing, to drag racing and sled pulling. Once built, the 10L1000 can be an especially versatile and capable transmission.