Edelbrock part #29575 Victor Pontiac EFI intake manifold is designed for use with 389-455 EFI competition engines. It 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. This intake manifold is machined for use with 4150 series carburetors and throttle bodies.