The Heavy-Duty version of cooler is the right cooler for all 6.0L diesel trucks that work and work hard. This means that if you have a DRW F350, F450 or F550 - you are going to want this heavy duty option. If you have an F250 or F350 (Single Rear Wheel) and you tow heavy or often with your truck, then this is the best option for you.
The Cold Weather Kit serves just like a coolant thermostat for the Bullet Proof Oil Cooler system. It is designed to allow your engine oil to warm up in cold weather climates before it circulates the oil through the air-to-oil cooler. Keep in mind, the Bullet Proof air-to-oil cooler is designed to work in hot summer climates like Phoenix, Arizona. This means that it will work exceedingly well in Alaska in January. Good rule of thumb? If you think you might need the cold weather kit, then you should buy it.