Slammer Redux: Chevrolet Performance’s 1969 Chevelle Now has the SP502/605 Crate Engine

The 1969 Chevelle “Slammer” is one of the most photogenic vehicles in the impressive Chevrolet Performance fleet. At the end of the 2000s, it graced the pages of HOT ROD magazine, with the editors performing eight engine and transmission swaps in the car to make numerous quarter-mile passes.

The Chevelle was built for those types of heart transplants, and today, its heartbeat is a Chevrolet Performance SP502/605 crate engine.*

The Dazzling Black car^† made the rounds on this year’s HOT ROD Power Tour, and during the Bowling Green, Kentucky, stop at Beech Bend Park, GM Integration Technician Bill Graham covered the Chevelle’s details.

Long after its days as a magazine model, Graham’s team found the car in the scrapyard at the Milford Proving Ground in 2016. The Chevelle went to the 2016 SEMA Show to showcase an LT*-based engine, and it was on Power Tour the following year.

However, it wasn’t shown a lot, and the build was a perfect choice to renew with a new Big-Block in 2024.

“We decided to bring it out of the heritage group and put in an SP502/605 with a 4L85-E transmission,” said Graham, an 11-year GM employee who has worked on projects with the company for more than 30 years. “Everything underneath [the Slammer] was capable of the horsepower and torque when it was originally built with the LT motor.”

As its name implies, the SP502/605 displaces 502 inches and cranks out 605 horsepower. It also makes 480 lb.-ft. of torque. The power plant is based on the ZZ502/502,* but the SP502/605 utilizes component upgrades including higher-compression pistons, a new hydraulic-roller camshaft and CNC-ported oval-port heads for greater output. It also sports valve covers featuring an etching reading “502.”

In many ways, the current incarnation of the Chevelle carries on the Big-Block tradition from the muscle-car era.

“A lot of Chevelles were originally built with 396s and 427s, so it fits perfectly,” Graham said.

In the Slammer, the engine incorporates stainless-steel headers and gasses are spent through a performance exhaust system, providing a throaty rumble.

Meanwhile, the Chevrolet Performance SuperMatic 4L85-E four-speed automatic transmission features a 685 lb.-ft. torque-capacity limit.

The car sits on its original chassis, but an air-adjustable suspension helps provide a mean, low stance. The forged-aluminum wheels measure 18x8 in the front and 20x10 in the rear, while Chevrolet Performance Brembo brakes with concept rear calipers and slotted rotors bring the Chevelle to a stop.

“We actually designed different caliper-mounting brackets and stuff like that to carry some of our performance parts into our vehicle,” Graham said. “We try to adapt as many parts as we can to our show-car builds.”

Exterior modifications on the Chevelle include an aftermarket front spoiler and polished grille inserts.

The leather interior is Adrenaline Red with sixth-generation Camaro seats.

“We adapted those to the vehicle to give it some creature comforts,” Graham said.  

Other creature comforts include a horseshoe shifter, electric power-steering conversion, aftermarket gauge package, Bluetooth audio and keyless entry. 

Inside and out, the Chevelle and its SP502/605 crate engine are a celebration of American muscle — across multiple generations.

Be sure to keep watching The BLOCK for more Chevrolet Performance builds from the biggest events nationwide.

*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.

^†Vehicle shown not available for purchase.