The Dart Big Chief manifold gives you the benefits of a custom made sheet metal manifold without the time and expense. This casting incorporates the Big Chief’s radical spread port design which promotes phenomenal airflow. Carburetor pads are specifically designed for 4150 & 4500 carbs. Optimized runner cross-sectional area maintains high mixture velocity for maximum power. Individual runners provide a line-of-sight path from carburetor to ports. Dual distributor hold-downs simplify timing adjustments. Bosses for rear coolant lines are provided.