Edelbrock part #2957 Victor Pontiac intake manifold is designed for 389-455 competition engines using standard flange carburetors. This manifold is ideal for drag racing (Super Stock, Super Gas, Super Comp, Brackets, etc.), marine or any application requiring maximum power up to 7500 rpm. Compatible with standard Pontiac cast iron heads, or use with Edelbrock Performer RPM Pontiac aluminum heads for maximum power. Port exit size at head is 1.08" x 2.10" with enough material to open it up to larger port openings.