Edelbrock part 5409 Performer RPM Dual - Quad intake manifold is designed to fit 1958 - 1965 Chevrolet 348409 W big - block engines with factory large port or with our Performer RPM W - series heads 60809 or 60819. The manifold deliver performance with Edelbrock Performer Series or Thunder Series AVS dual - quad carburetors, and they accept our dual - quad fuel lines, throttle linkage, and air cleaners. Includes Oil Fill Tube (not installed) and matching push - in Breather. Oil Fill Tube and Breather are also available separately as 4803. Carb center - to - center measurement is 6 - 716.