Designed for 1955-86 262-400 c.i.d. Chevy V8's for spread-bore (Q-Jet) or square-bore carbs. Delivers maximum power and a broad torque curve for high-performance street. Carb pad will accept square-bore carbs without adapters. #2504 Marine intake features brass lined front water crossover and brass flange inserts to cover the rear water openings. Performer RPM Q-Jet has same provisions as #7101. Will not fit under stock Corvette hood. CARB RECOMMENDATIONS: Edelbrock Thunder Series AVS or Performer Series (650-800 cfm) Carburetor. Use bracket #8031 or #8036 for 1972-78. #2504 and #2506 use #1409/#1410. INSTALLATION NOTE: Recommended intake gasket: Edelbrock #7201. Manifold height: A-4.20", B-5.25"; Carb pad height: 4.72". Port exit dimensions: 1.16" x 1.92". Use rod #9172 for divorced choke with Q-Jet. CAMSHAFT RECOMMENDATIONS: Performer RPM #7102, #2201 and #2204.