How much hp does a 7.4 liter 454 produce with aluminum heads and headers?

A 7.4-liter (454 cubic inch) engine with aluminum heads and headers typically produces between 400 to 500 horsepower, depending on the specific configuration and tuning. The use of aluminum heads can improve airflow and reduce weight, while headers enhance exhaust flow, contributing to increased performance. Exact horsepower can vary based on additional modifications and the overall setup of the engine.