PPE now has available new pressure calibration kits for the GM Allison 1000 series transmissions! This kit for the 2001-2010 model year transmissions serves as a great upgrade when building your 5- or 6-speed Allison 1000 transmission. This kit is highly recommended if you're hauling heavy loads or making high horsepower. The increased line pressure improves your clutches’ holding ability, and the calibration springs will tighten up your shifts. For more information, call 714-985-4825 or click here.