Holley LT1 Hi-Ram Intake Manifold (105mm W/ Fuel Rails)

PN - 300-140

The Holley EFI Hi-Ram Intake Manifold is engineered for maximum performance on the GM Gen V 6.2L LT1 direct-injected platform, offering high airflow and strong power in the 3500–8000+ RPM range. Its modular, removable-top design makes it easy to disassemble for custom porting, top swaps, or custom induction setups. The runners feature a smooth, high-radius plenum entry with optimized taper and cross-sectional area for broad performance across different engine combinations. Optional injector bosses allow for supplemental port injection alongside factory DI for added tuning and power potential.

Key Features & Specs

• Port size: 2.06” H x 1.53” W

• Runner length: ~6.5”

• Plenum volume: 549 cubic inches (with 95mm or 105mm top)

• O-ring seals at cylinder heads and plenum top for a leak-free fit

• Rear plenum machined for MAP sensor + 3 vacuum ports

• Head flange clearance for fuel supply to the high-pressure pump

• Increased runner wall thickness for custom porting at the runner/plenum entry

• Top options: 95mm, 105mm, dual 4150, dual 4500, or blank flange for custom throttle bodies

• Overall height: 13.34” (with EFI 95mm/105mm top)

• Height at plenum flange: 9.44”

• A-B height: 12.10” (with dual 4150/4500 carb-style top)

• Easy assembly with top-mounted plenum screws (except front two)

Injector/Fuel Rail Details (Injector Port Models)

• Includes anodized, laser-etched fuel rails machined for 8AN O-ring fittings on both ends

• Dual rail mounting supports injectors 1.48” or 2.56” (O-ring to O-ring)

• Injector spec: 40mm height (O-ring to O-ring) with 14mm O-ring diameter
  (Not compatible with LS2/LS3/LSA without a custom lower O-ring)