• Menu

Allison 1000 Transmission Stage 2 725HP Max

Call for Availability
Core Charge: +$1500

Stage 2 Allison 1000 - 725HP Max

2001-2019 Duramax


Allison 1000 Stage 2 725 Hp max

The Stage 2 Allison is our most popular high-performance transmission for the Duramax pickups; designed to handle up to 725 horsepower. This transmission is ideal for high-performance vehicles and heavy-duty trucks that require a reliable and durable transmission that can handle high power output. The Stage 2 Allison is built with heavy-duty components and features upgraded clutches, valve body modifications, and our in house built  torque converter. These upgrades allow the transmission to handle the increased power output while maintaining smooth and consistent shifting. The Stage 2 Allison is a popular choice among performance enthusiasts and truck owners who demand the best in performance and reliability.


  • Raybestos or ALTO G3 C-3 C-4 Torque kit custom machined pressure plates
  • LML style pistons and return springs
  • Raybestos or ALTO G3 C-1, C-2 Torque kit
  • Ratio Tek pressure upgrades
  • Transgo trim valves
  • New torrington bearings
  • Randy’s Torque converter with billet stator
  • New OE filters
  • HD Cast Aluminum deep pan
  • Flexplates are not included on Allison builds to shops or retail
Write Your Own Review
You're reviewing:Allison 1000 Transmission Stage 2 725HP Max
Your Rating


2 Year unlimited mile limited warranty will not cover broken cases or shafts of transmission. Abuse, misuse, or burn down due to operator error will void warranty. Any warranty work must be performed at Randy’s Transmissions in Tooele UT. It is the vehicle owner’s responsibility to ship transmission or vehicle to Randy’s location for any and all repairs needing to be performed. Any repairs to transmission not authorized by Randy’s Transmissions will void warranty and will not be covered by Randy’s Transmissions.


Appropriate gear ratios

  • 35" tire min gearing is 3:73 recommended 4:10
  • 37" tire min gearing is 4:10 recommended 4:30
  • Larger than that should be running a 4:56 ratio