The Speedmaster LowRise Manifolds are our lowest profile manifold and is also the only one that is street legal on pollution controlled vehicles. It is set up to accept a spread bore carb but comes with an adapter plate that permits the use of square bore carbs. To remain street legal with a square bore carb, you must use one that is also approved as street legal for your application.
This Speedmaster LowRise manifold is a direct replacement manifold for the stock manifold on Chevy big block engines with general duty oval port heads. See note below for specifics. This manifold will not fit under the hood of Corvettes without hood modifications. Will not fit -tall block- V8s. May be used with OEM or aftermarket carburetors. For street applications use the stock Quadra-Jet carburetor. For street performance use a 650-750 cfm performance or double pumper carb and for competition use a 700-850 cfm double pumper. Note that the Speedmaster Manifold kit includes a carb adapter plate and gasket to allow the use of square bore carburetors. Square bore carbs on this manifold are not legal for use on any emission controlled vehicle. Will fit 1965 through 1990 oval port cylinder heads. Use a Professional Products #53600 gasket or a Fel-Pro #1210 (non-Printoseal) or #1212 (Printoseal) intake gasket with this manifold.