Edelbrock part #21011 Performer intake manifold is designed for street 1955-86 small-block Chevys. Edelbrock's Patented Dual-plane, low-rise design with a 180-degree firing order greatly improves torque over a wide rpm range for excellent throttle response from off-idle through 5500rpm. Not for 1987 and later cast iron or Chevy Bowtie heads. Will fit 1987 and later stock aluminum heads. This manifold offers a polished finish for a brilliant shine and classic look.