Hi-Ram Lower Manifold GM LS1/LS2/LS6-Black LS1/LS2/LS6 Cathedral Port Carbureted Base Only (plenum-Top-Mounting Fabrication Flange Available) HolleyIntended for use on N A or forced induction engines in the 6. 0 to 7. 0+ liter range, max power at 7000 8000+RPM. The base is designed to be modular in configuration to accept a wide range of carbureted and EFI tops and to be attractive to builders and fabricators as the foundation for custom induction systems. The Holley Gm LS1 LS2 LS6 Modular Hi Ram Intake Manifold is introduced as a cost effective alternative to fabricated sheet metal for high