311241033 Stage 3 Allison 1000 Transmission 900HP Max

Features:

• Supports up to 900 horsepower
• Built for 2001–2019 Duramax trucks
• Includes billet input shaft
• Custom-machined pressure plates
• Raybestos or ALTO G3 torque kits
• Billet C-2 hub for added strength
• HD cast aluminum deep transmission pan
• Randy's billet stator torque converter
• Transgo trim valves for improved response
• New OE filters included
• Upgraded torrington bearings throughout
• Ratio Tek pressure system enhancements

Built for Trucks That Don’t Back Down

If your Duramax is pushing serious power and you’re tired of babying your transmission, it’s time to step up to something that can actually keep up. The Randy's Stage 3 Allison 1000 is built with heavy-duty performance in mind, handling up to 900 horsepower without flinching. Whether you're laying down rubber at the strip or towing massive loads through the mountains, this transmission gives you the confidence to push harder without worrying about what’s happening inside the bellhousing. It's designed specifically for 2001 to 2019 Silverado and Sierra 2500HD and 3500HD models with the 6.6L Duramax, making it a direct upgrade for serious builds that demand more than stock components can offer.

Heavy-Duty Parts Where They Matter Most

This isn’t just a stock rebuild with a few tweaks, it’s a complete performance package from the inside out. You’re getting premium internals like Raybestos or ALTO G3 torque kits for the C1 through C4 clutches, paired with custom-machined pressure plates and LML-style pistons for stronger, more reliable engagement. Ratio Tek pressure upgrades and Transgo trim valves fine-tune the system to handle higher power levels smoothly. The torque converter is Randy’s own, featuring a billet stator built to transfer power with authority. Additional upgrades like billet input shafts, a billet C-2 hub, new Torrington bearings, and a cast aluminum deep pan all contribute to long-term durability under stress. It's a transmission built for hard use, whether you're racing, towing, or just driving like you mean it.

Fitment: 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax