Dodge's Challenger and Charger SRT Hellcat models rewrote the rule book on affordable performance following their debut almost a decade ago, but now their run is about to come to an end.

The 2023 model year is the last for the performance duo, as Dodge parent company Stellantis will cease building their supercharged 6.2-liter V-8 engines at the end of the year.

Hennessey has been offering 1,000-hp versions of the cars for several years and the Texas performance marque is celebrating the run with a final-edition upgrade known as the H1000 Last Stand package.

The upgrade is available for Challenger and Charger SRT Hellcat models from the 2021-2023 model years, and production is limited to 50 examples. With 1,000 hp on tap, the upgrade delivers performance that's just 25 hp shy of the wild Challenger SRT Demon 170's output. However, the Hennesseys achieve their output on regular pump gas while the Demon 170 requires E85. Otherwise output drops to 900 hp.

Quoted performance for both Hennesseys include a 0-60 mph time of 2.8 seconds and a quarter-mile time of 9.9 seconds at 141 mph.

Key modifications include a larger supercharger (non-Redeye models only), a pulley upgrade, a new throttle body, long-tube headers, high-flow catalytic converters, upgraded fuel injectors, and a high-flow intake. All of the modifications are tuned and honed on a chassis dyno to make sure everything works in harmony, and each car undergoes extensive road and track testing. Hennessey backs its upgrades with a three-year, 36,000-mile limited warranty.

To make the cars stand out, they feature a custom rear spoiler, rear diffuser, front splitter, and side skirts all made from carbon fiber. There's also a Last Stand graphics package, plus unique 20-inch wheels that the buyer can order in gloss black or gray. The final touch is a serialized plaque signifying the car's position in the 50-build run.

2023 Hennessey H1000 Last Stand Challenger SRT Hellcat

2023 Hennessey H1000 Last Stand Challenger SRT Hellcat

Pricing for the upgrade alone starts at $64,950. Customers supplying a Redeye as the donor get a discounted $54,950 price, as there's no need to upgrade the supercharger.

Hennessey also has a 1,000-hp sendoff for the current-generation Chevrolet Camaro which bows out after the 2024 model year.

While Chevy remains quiet on what comes next for the Camaro, Dodge has already confirmed electric replacements for the void left by the Challenger and Charger. It previewed one of those replacements last year with its Charger Daytona SRT concept.