Making an estimated 400 horsepower and 450 lb-ft of torque is a fuel-injected 8.1L big-block V-8 engine out of a ’04 Chevy Suburban 2500. It uses a Fuel Injection Specialties wiring harness and has Hedman headers, 3½-inch-diameter exhaust, and a Flow Master muffler. A Derale cooler with 8-inch fan cools the power steering fluid and engine oil. A pair of RedTop Optima batteries are mounted underhood as well. Power from the big V-8 is sent to a TH400 transmission that has been upgraded with 4L80E sprags, a shift kit, and a factory Dodge cooler. A StaK Monster three-speed transfer case splits the power to the Rockwell’s via custom driveshafts from Drive Products that have 1410 U-joints.