This plenum base adapter converts Holley's LS1/LS2/LS6 cathedral-port Mid-Rise 2x4 intake manifold into a Mid-Rise EFI intake by accepting Holley's Hi-Ram plenum tops, and is also sold separately for custom modular intake builds. At a max height of 10.44", it suits street and street/strip applications with a 1,500-6,500 RPM powerband, including blow-through and turbocharged setups.
Specifications:
- Material: Aluminum
- Product Type: Intake Manifold
- Sub Category: Service Kits
- Type of Component: Manifold Top
- Warranty: Manufacturer's Limited 90 Day Warranty
- Part Number: 300-267
Intended for GM LS Gen III or IV engines with LS1/LS2/LS6-style cathedral port cylinder heads; ECU recalibration may be required. An adapter harness (P/N 558-416) is available to convert LS1/2-style MAP sensor connections to the recommended LS3 MAP for this manifold.
FAQ
What does this adapter do?
It converts Holley's LS1/LS2/LS6 Mid-Rise dual-plane intake base into a Mid-Rise EFI manifold by accepting Holley's Hi-Ram plenum tops.
What engines is it designed for?
GM LS Gen III or IV engines with LS1/LS2/LS6-style cathedral port cylinder heads.
What RPM range is it optimized for?
A 1,500-6,500 RPM powerband, suited to street and street/strip use including blow-through or turbocharged applications.
