Desert Bounty: The 525 RLB Crate Engine Goes to Unlimited Truck SPEC Winners 
 

Throughout the 2024 season, an extra incentive was available for winners of the Unlimited Truck SPEC class at each prestigious Unlimited Off-Road Racing event in the western United States. It came in the form of a Chevrolet Performance 525 RLB crate engine.* 

Three winners took home the new LS-based power plant for their efforts: Justin Davis in the Parker 400; Kyle Jergensen the Mint 400; and Jack Olliges in the California 300. Each 525 RLB was provided by AutoNation and Klein Engines. To be eligible, racers only needed to run an Auto Nation Crate by Klein Engines decal on either side of their truck. 

For years, many of the engines in off-road spec classes have been based on a version of the Chevrolet Performance LS376/525,* but rules allowed for various upgrades. Thus, racers were forced to pay for the modifications that come standard in the 525 RLB. 

The 6.2L engine is offered as a long-block assembly and is based on Chevrolet Performance’s CT525 circle track* crate offering. The 525 RLB makes 533 horsepower and 477 lb.-ft. of torque with a four-barrel carburetor and intake manifold. It utilizes LS3 rectangular-port cylinder heads, forged pistons and heavy-duty connecting rod bolts. The engine also features coil-on-plug ignition, an SFI-certified balancer and a six-quart racing oil pan. 

However, the 525 RLB comes without an induction or ignition system, allowing builders to complete the power plant with the best components for their needs. That also makes it a good choice for multiple sanctioning bodies where rules may vary in those areas. 
 
The engine has been added to the rulebook in several off-road series, and the engine’s sealed nature allows for easier tech inspection.   

In 2024, each Unlimited SPEC Truck event featured a close contest, capped by Olliges’ victory in the California 300 where he took the victory by just 63 seconds after 300 miles. He finished third overall in addition to winning the class. 
 
Details for the 2025 program are still being finalized, but the 525 RLB is set to be under the hood of multiple trucks throughout the desert. 
 
Keep watching The BLOCK for much more on Chevrolet Performance, off-road racing and all motorsports disciplines. 
 
*Because of their effect on a vehicle’s emissions performance, these engines are intended exclusively for use in competition vehicles. These engines are designed and intended for use in vehicles operated exclusively for competition: in racing or organized competition on courses separate from public roads, streets or highways. Installation or use of these engines on a vehicle operated on public roads, streets or highways is likely to violate U.S., Canadian, and state and provincial laws and regulations related to motor vehicle emissions.