A system designed to replace the original powerplant in a specific model of a full-size sedan with an alternative, often higher-performance, engine. These systems commonly include necessary mounting hardware, wiring harnesses, and potentially modified driveline components to facilitate the installation process. For instance, a kit might allow replacing the factory V6 with a more powerful V8 engine.
The utilization of these systems offers a pathway to substantially increase vehicle performance beyond the factory specifications. Historically, these modifications provided a means to modernize older vehicles or customize them to meet specific performance goals. This approach can breathe new life into an existing vehicle, avoiding the cost associated with purchasing a completely new car.