Keeping cool is top priority. No, we're not talking about iPhones, big rims, or overpriced jeans. The cool we covet is our powertrain's vital fluid temperatures. While the operating temp of the engine is generally determined long before it sits between the vehicle's framerails, maintaining those heat numbers once the powerplant is running under the hood is not always simple. Since our '99 Dodge Durango's factory 5.9L radiator wasn't designed for the heat and volume of the new Viper V-10 engine, we tossed it aside. After taking a few measurements and consulting with our expert Viper tech, Tom Sessions, we decided on a high-flow aluminum radiator and electric fan system from Flex-a-lite. For years Flex-a-lite has offered performance cooling systems for both OE and custom applications. When we presented them with the challenge of keeping our 505ci cool in extreme conditions, they were ready for the test. With our Mopar Monster still being operated on by the crews from National Speed and Momentum Performance in Wilmington, North Carolina, we continue to cut and craft our way through the project. Putting the fabrication skills of both performance shops to the test, we molded our aftermarket cooling system into place and started work on the interior reassembly. The massive Flex-a-lite aluminum radiator is designed to flow and cool the engine's coolant more rapidly than a traditional unit. While there are direct replacement radiators available, we opted for a larger unit since the V-10's 500-plus horses are sure to cook up a lot of heat.The massive Flex-a-lite aluminum radiator is designed to flow and cool the engine's coolan Another advantage of a custom radiator is the ability to change the location of the inlet and outlet. Even with the 8.3L pushed back a foot into the custom firewall, the space for our radiator hoses was limited. Rather than build an overly long and complicated hose setup, we modified the inlet and outlet to allow for a cleaner and more direct fit.Another advantage of a custom radiator is the ability to change the location of the inlet To ensure that both the engine and transmission have adequate fluid cooling, each received an individual cooler that attaches to the front of the radiator. Using the provided pull-through attachment ties, the standalone coolers use the fresh air being pushed through the grille to keep the oil cool, which prolongs the life of the high-performance components.To ensure that both the engine and transmission have adequate fluid cooling, each received Since factory Viper platforms use a hydraulic fan configuration, we opted for an easy-to-control electric twin puller fan setup from Flex-a-lite. The puller fans work great to pull fresh air through the radiator at low speeds. Since they are electric, we wired them up to a separate switch in addition to the auto thermostat relay. The idea behind the switch is so when we encounter deep water or mud, we can turn the fans off to prevent damage to the cooling components.Since factory Viper platforms use a hydraulic fan configuration, we opted for an easy-to-c Spacing for the new cooling setup is pretty limited. We still need to have hoses made and build a shroud, but installation of the system is nearly complete. Since we are fitting the Mudder with A/C and have multiple coolers, we are leaving room for a pusher fan to mount in the front just in case our temps get a little hotter than we like.Spacing for the new cooling setup is pretty limited. We still need to have hoses made and Vipers are known for cabin heat, and since nobody likes feeling cooked inside his ride we created this custom HVAC system that uses pieces from the Durango's factory system. We know, we know-who needs A/C in a giant mud truck? Well, our Durango's leather seats can seat seven comfortably and we wouldn't want our mutated grocery getter to melt all the ice cream before we get home, now would we?Vipers are known for cabin heat, and since nobody likes feeling cooked inside his ride we We decided long ago that we didn't care to keep the factory gauge cluster. We will still have the ability to read codes from the OBD-II port, but didn't want to see our information center blinking at us nonstop. This left us with a big hole in our dash and an opportunity to get creative with our new Auto Meter gauges.We decided long ago that we didn't care to keep the factory gauge cluster. We will still h With a little careful planning and the help of a computer-guided plasma cutter, Momentum Performance cut out an aluminum gauge holder to sit in place of the original gauge cluster. Once we determined the layout and gauge placement, we dropped the level readers in for a quick test fit.With a little careful planning and the help of a computer-guided plasma cutter, Momentum P We opted for Auto Meter's Phantom II series gauges to fill out the dash: fuel level and pressure, oil pressure and temp, coolant temp, transmission temp, tachometer, and voltmeter. Beyond Auto Meter's legendary name and quality, another reason we went with the gauges was the company's exclusive working relationship with Chrysler's Viper engineers. The relationship allowed us to tap our Monster tachometer directly into the Viper's harness without any issues.We opted for Auto Meter's Phantom II series gauges to fill out the dash: fuel level and pr Next Month Since we've sliced and diced almost every mounting bracket and tab on our dash, we still have a little work to do before we can finish our interior. Be sure to check us out next month as we tackle the dreaded wiring harness and finish up a few loose ends on our cooling system and interior. SOURCES Auto Meter 413 W. Elm Street Sycamore IL 60178 866-248-6356 www.autometer.com Momentum Performance Wilmington NC www.momentumperformance.com Flex-A-Lite 7213-45th St Ct E Fife WA 98424 800-851-1510 www.flex-a-lite.com National Speed Inc. Wilmington NC www.nationalspeedinc.com By Ali Mansour Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!