Menu

Shop

Garage

Cart

Account

Key Specs

MFG. Part #300-242
BrandHolley
See more specs

Need To Know

Quick and Easy Returns

Return Policy

Holley 300-242 Details

The EFI Hi-Ram manifold line has a new addition for the 351W Ford application. This manifold comes with a 105MM LS throttle body flange top, a 95mm LS throttle body top is also available. The runner length and tapered cross section design will perform well for a wide range of engine combinations. The engineering team also redesigned the water crossover passage to allow room for distributor phasing. Aggressive, bold, race-bred styling will make bad intentions clear for drag race, muscle car, marine, off-road, sandrails, pulling trucks, track, street-rod applications and more!Manifold is designed for a 9.5" deck height.Manifold width is 11.32".

  • Runner length and the tapered cross-section designed to perform well for a wide range of engine configurations
  • EFI fuel rails are machined for -8AN O-ring Fittings with passages large enough to accommodate high fuel flows and dampen pressure pulsations in the fuel system and come standard with EFI Hi-Ram kits.
  • Cast aluminum construction.

    Features:

  • The 351W manifold is available to work with 95MM or 105MM GM LS throttle bodies
  • EFI fuel rails are machined for -8AN o-ring fittings with passages large enough to accommodate high fuel flows and dampen pressure pulsations in the fuel system and come standard with EFI Hi-Ram kits.
  • Plenum Top Gasket Type – 3/32” Round O-ring Cord
  • Manifold is designed for a 9.5" deck height.
  • Requires the Use of Holley EFI Dual Sync Distributor - 565-111
  • Rebates

    Holley Fuel Up Spring Savings Event 2026

    Save 10% instantly on select products across the Holley family of performance brands during the annual Holley Fuel Up Spring Savings Event 2026. Instant rebate period runs from March 30, 2026 through April 19, 2026.

    CARB Warning

    For race/ off road use or for use on pre-1966 vehicles.

    Emissions warning: this part only legal for sale or use in California for racing (competition) vehicles which may never be used, registered, or licensed for use upon a public highway, or if installed in vehicles model-year 1965 or older; motorcycles model-year 1977 or older; or off-highway recreational vehicles (such as off-road motorcycles and all-terrain vehicles) model-year 1996 and older. Any other use renders the vehicle tampered and not legal for use on California public highways (any public street or roadway, public dirt road, public park, or publicly maintained right of way open to the use of the public for vehicular travel). Violations subject to $37,500 penalty per violation per vehicle, revocation of registration, loss of use on California public right of ways, and proof of correction for tampering. There are similar restrictions and penalties under federal law and the laws of all other states with penalties under federal law of up to approximately $45,268 per tampered vehicle and/or engine.

    Holley 300-242 Specifications

    KEY SPECS
    MFG. Part #300-242
    BrandHolley
    GENERAL
    GTIN Code090127029145
    Customer Impersonation Script