300-261 Holley Single Plane Intake Manifold- Chevy Small Block V8. The carburetor-mounting pad is designed to accept all stock or aftermarket square-bore carburetors with manual or electric chokes. These intake manifolds are designed to accept most stock hardware and accessory brackets, but offer performance features; like an updated plenum divider area, a 1 shorter height than the 300-25 manifold, and a choice of two distributor clamp locations. The isolated design of the air/fuel passages helps to increase charge air density and performance. The 300-261 intake manifolds are designed for square-bore carburetor applications on 1957-86 262-400cid Small Block Chevrolet engines and SBC engines equipped with 1987-91 L98 aluminum Corvette cylinder heads (non-EGR applications).Also, these manifolds will work with any SBC engine equipped with aftermarket cylinder heads, as long as they have a standard port flange opening and mounting bolt locations. Holley Factory Refurbished Items are warranted for a period of 90 days from date of sale for defects in material and workmanship. Any defective items will be repaired or replaced at Holley's discretion. So we have a chance to make it right - we want your repeat business! Check out the official Holley Performance.