Edelbrock Victor series Drag Race headers are designed specifically for competition, with the design parameters optimized for maximum power production in a drag-race setting. They are engineered to deliver the correct firing-order pulse sequence in the collector. In addition, they are built with rugged, laser-cut header flanges and have an expansion cone at each collector exit. This slip-on configuration allows easy tuning of primary lengths to suit your engine. After tuning is complete, you can weld the retainer brackets and scavenger pipes if you desire.