Detroit Diesel, GM/CHEVY/GMC/AMG/GEP Optimizer 6.5/6.5T/6.5SC 'Aussie' Diesel Cooling Upgrade System (for trucks converted to 6.2/6.5 engines)
Detroit Diesel, GM/CHEVY/GMC/AMG/GEP Optimizer 6.5/6.5T/6.5SC 'Aussie' Diesel Cooling Upgrade System (for trucks converted to 6.2/6.5 engines)
Detroit Diesel, GM/CHEVY/GMC/AMG/GEP Optimizer 6.5/6.5T/6.5SC 'Aussie' Diesel Cooling Upgrade System (for trucks converted to 6.2/6.5 engines)
Detroit Diesel, GM/CHEVY/GMC/AMG/GEP Optimizer 6.5/6.5T/6.5SC 'Aussie' Diesel Cooling Upgrade System (for trucks converted to 6.2/6.5 engines)
Detroit Diesel, GM/CHEVY/GMC/AMG/GEP Optimizer 6.5/6.5T/6.5SC 'Aussie' Diesel Cooling Upgrade System (for trucks converted to 6.2/6.5 engines)
Detroit Diesel, GM/CHEVY/GMC/AMG/GEP Optimizer 6.5/6.5T/6.5SC 'Aussie' Diesel Cooling Upgrade System (for trucks converted to 6.2/6.5 engines)

Detroit Diesel, GM/CHEVY/GMC/AMG/GEP Optimizer 6.5/6.5T/6.5SC 'Aussie' Diesel Cooling Upgrade System (for trucks converted to 6.2/6.5 engines)

Regular price $335.00 Sale

PARADOX AMG/GEP Optimizer 6.5/6.5T/6.5SC 'Aussie' COOLING UPGRADE System (patent pending)

This is simply the best bang for the buck upgrade you can make to your truck, period! Must do before any performance or horsepower mods.

All trucks converted to AMG/GEP Optimizer V8 6.5 engines share an inherent design flaw in their cooling circuit.  Due to the packaging of the cooling system, coolant distribution is disproportionately fed to the front of the engine block and heads.  The rearmost cylinders run significantly hotter due to this inadequacy, while the fronts are overcooled. Diesel engines run best in a tight band of temperature.  In the earlier 6.2 engines these higher rear temperatures led to many of the well known failures in those engines which are nearly always in the rear two cylinders.  Later blocks had the dreaded #8 cylinder failures. Later even with increased block density and better metallurgy, among other improvements, to reduce the catastrophic failures they never addressed the cooling imbalance and the loss or performance from it.   

Paradox developed our system using proven technology from our Motorsports background.  The Motorsports industry has long known of the benefits to balancing the temperatures across V8 engines, especially when running at the cutting edge of detonation needed to make maximum power.  While that may not be the goal of most truck owners, cooler running temperatures, better power and efficiency are.  Further the reduced heat from the rear of the engine is a welcome reprieve from hot cabin temperatures, too.   On average, the mechanical and/or electric fan(s) cycle on 25%-50% less than stock with our kit installed.  This is one of the most obvious advantage to our kit as this greatly reduced the loss of power, added noise and fuel burn!

The Paradox system opens up the blocked off rear coolant area of these engines and allows for flow to the front of the coolant circuit. By opening this up we create coolant flow to the once dead area of the block. The added benefit is reduced air/steam pockets and constant coolant bleeding to the overflow tank. Countless hours of testing and tuning went into developing this kit with the proper flow for maximum benefit, as well as to assure proper match to the front of the block. Diesel engines need to operate in a narrow band of temperature to maintain optimum efficiency.  Without our kit the front of the block is over-cooled and the rear under-cooled, leading to loss of power and efficiency. Our system is hand assembled in the USA with all USA made parts.  We use Aerospace certified AN fittings, high temperature/pressure stainless steel braided hose with a soft outer layer to not cut into your soft metal parts. We fabricate a custom bolt on replacement for the rear coolant block off plates which includes new gaskets as well.  Everything is a true bolt-on system (unless otherwise noted below). The complete kit is in black. Should you desire to remove the system it is fully reversible as well.  All systems come with a color step by step guide for installation.  Buy with confidence with a full one year warranty against manufacturer defects and workmanship.

Please carefully choose from three available options at checkout.  If you are not sure which to order, please contact us to confirm you are getting the proper kit.

Fits all:
Vehicles that have swapped engines to a Detroit Diesel, GM/CHEVY/GMC/AMG/GEP Optimizer 6.5 Diesel engines. This is NOT generally a bolt-on kit and requires fabrication to fit your custom application!! If your truck was originally equipped with a 6.5 diesel this is NOT the kit for you!
The 'Aussie' Kits all come with a 1/8" NPT swivel return fitting that needs to be installed into the thermostat housing area. Many original 6.5s have this fitting already which is the bleeder, but many new Optimizers or aftermarket set-ups do not have the bleeder. If you do not have the bleeder you will need to drill and tap into your thermostat assembly or piping to install it (in cold climates we install this return pre-thermostat(s) to aid in faster warm up but ultimately it will not effect the performance of the kit if installed after them). All three versions also come with a special assembly to allow for a heater hose to run from one of the rear plates. We provide a 'T'ed assembly which has an open female port sized 1/2MPT. With this you should be able to locally procure a male 1/2MPT to nipple (for whatever size hose you intend to run for your heater).
There are two options which cover most 'Aussie' non-OEM conversions:
  • Non-Turbo 6.5 and Turbo 6.5
  • Supercharged 6.5 (extra length to run lines around the supercharger). 

Some pictures represent generic installations and are for reference only.
NOTE!!  THIS KIT WILL NOT FIT OEM Installed Chevy/GMC 6.2/6.5 applications or MILITARY HMMWVs, or CUCVs or ANY 6.2ltr vehicles originally equipped!  Please return to the 'PRODUCTS' page and look for your correct application!