Motorsport competition organizer UNLTD Off-Road Racing has announced the latest updates for the 2024 UNLTD Off-Road Racing Rulebook, set to go into effect next month. Among the updates is specification of the LS-based 6.2L 525RLB high-performance GM engine for use in the Unlimited Truck Class. UNLTD Off-Road Racing organizes a variety of high-profile events, including the Mint 400, Parker 400, and California 300.
“UNLTD Off-Road Racing will require all entrants in the Unlimited Truck SPEC Class to have a GM factory tagged engine. This will save racers money and level the playing field,” said Unlimited Off-Road Racing CEO, Matt Martelli.
The spec GM engine is available from Chevrolet Performance and is rated at 533 horsepower at 6,600 rpm and 477 pound-feet of torque at 5,200 rpm with a four-barrel carb. Highlight features include all-aluminum construction, with a cast-aluminum block and six-bolt, cross-bolted main caps, LS3 rectangular port heads, forged pistons, performance rings, heavy duty bearings, upgraded connecting rod bolts, an SFI-certified Racing Harmonic Balancer pinned to the crankshaft, racing oil pan, and racing vented valve covers.
The compression ratio is set at 10.7:1, with a hydraulic roller cam, 4.065-inch bore, and 3.62-inch stroke. Maximum recommended rpm is set at 6,700. The engine is similar to the 6.2L CT525, but is sold as a sealed long block for racing purposes. Customers are required to add induction and ignition control systems, a starter, fuel system, exhaust, and front accessory drive system.
“We have identified a select group of dealers that teams will be able to order these engines through, as well as qualified builders who can set them up and deliver race ready engines,” Martelli said.
Racers that wish to compete with engines that no longer fall under the updated Spec Class rulebook are invited to compete in the Unlimited Class.
“This class has a healthy amount of entries and this decision will foster its growth even further,” Martelli added.