Holley 300-267 Mid-Rise Plenum Base Adapter Kit - GM LS1/LS2/LS6

The Modular Mid-Rise intake utilizes the popular Holley LS1/LS2/LS6 cathedral port Mid-Rise 2 x 4 intake manifold along with a plenum base adapter and a Holley 92MM EFI plenum top which converts it into a Mid-Rise EFI intake manifold.

Part Number: 300-267

For use with LS Dual Plane Mid-Rise intake manifold base to adapt to modular tops. The Modular Mid-Rise intake utilizes the popular Holley LS1/LS2/LS6 cathedral port Mid-Rise 2 x 4 intake manifold along with a purpose built plenum base adapter and a Holley 92MM EFI plenum top which converts it into a Mid-Rise EFI intake manifold. With a max overall height of only 10.44", the Mid-Rise manifold is an excellent choice for street and performance street/strip applications with a powerband from 1,500-6,500 RPM and limited hood clearance. It's perfect for a blow-thru or turbocharged application. Being part of the Holley modular intake line means that this intake is not only available as a complete kit with intake, adapter, 92MM top and fuel rails, but all parts can also be purchased separately for a custom intake build. The plenum adapter (PN 300-267) will accept all of the popular Holley Hi-Ram plenum tops as a foundation for custom induction systems.

Features and Benefits

• Provides great performance to 6500 rpm for street/strip performance applications while providing the look of a racing EFI intake manifold
• Unique modular design allows the combination of a traditional dual-plane layout with an EFI manifold plenum to produce great mid-range torque without compromising top end power
• Great for supercharged or turbocharged engines
• Power band from 1500-6500 rpm
• May require an aftermarket hood for some vehicle applications.
• Cast aluminum construction
• Intended for use on all GM LS Gen III or IV engines equipped with LS1/LS2/LS6 style cathedral port cylinder heads (recalibration of the ECU may be required when using this intake manifold design with OE ECU).

Holley EFI LS main harnesses have a map sensor connecter designed for use with an LS1/2 style map sensor. The 558-416 is an adapter harness that can be used to adapt any LS harness that uses a LS1/2 MAP sensor connection to a LS3 MAP, which is recommended for this manifold.