Hole size tapers from approximately 1.65" to 1.71"
Bolt on performance gains with this Holley Aluminum 1 Inch Carburetor Spacer. Improved low-end torque and throttle response. Boost performance and driveability for all major 4150/4160 style carburetors such as Holley, Demon, Edelbrock, etc. 4-hole tapered design, ports taper from 1.65" to 1.71". Comes with gaskets and mount studs for a smooth install. Tapered 4-hole design Fits 4 barrel Holley carburetors