Edelbrock SBC Perf Air Gap ManifoldEdelbrock part #2601 Performer Air Gap intake manifold is designed for 1955 86 262 400 c. i. d. small block Chevys. This Performer Air Gap intake manifold features an air gap design for the ultimate street performance in the idle to 5500 rpm range. This design features an open air space that separates the runners from the hot engine oil resulting in a cooler, denser charge for more power. High velocity runners deliver excellent throttle response