Holley’s new all-aluminum 830 cfm classic HP carburetor features a contoured venturi inlet for balanced airflow, screw in air bleeds for precision tuning capabilities, high flow metering blocks and Dominator-style fuel bowls, which allow plumbing from either side for ease of installation. Holley HP carburetors are the standard for square bore race carburetors. Race ready, out of the box.

This model of carburetor has the square bore flange bolt pattern. It can replace Holley, Edelbrock, Carter AFB, and Autolite-style carburetors with 5 3/16″ x 5 5/8″ bolt pattern. If you have a spread-bore style intake manifold, you will need an adapter to install this carburetor. Similar to the Mr. Gasket #1932.
For more info: https://www.holley.com/