Introducing carb hats from Holley EFI. These new carb hats are the perfect solution for any blow through installation. The Holley EFI carb hats contoured designed promotes optimal airflow, while providing excellent hood clearance for most applications with a 5-1/8" air cleaner flange. These hats feature a 1/8th NPT reference port that can be used as a convenient hookup for boost gauges or carbureted fuel pressure regulators . The inlet is designed for a 3.5" silicone coupler, with a sealing lip to ensure a leak free installation.