JK 400 CFM Big Block Chevy Cylinder Heads with as cast ports. (Price per pair BARE) Upgrade:Select Option CNC intake and exhaust ports

CNC intake and exhaust ports with CNC chambers

5" Deck BA Intake Manifold

0" of area at the plenum and of the runner

8" MCSA Intake Ports

JK 400 CFM Big Block Chevy Cylinder Heads with as cast ports. (Price per pair BARE) Upgrade:Select Option CNC intake and exhaust portsPRODUCT DESCRIPTION The CID JK400 Big Block Chevy Cylinder Heads flow an impressive 400CFM from as cast ports on a standard bore! This allows us to offer serious performance from an affordable cylinder head and intake package. These symmetrical port BB Chevy cylinder heads no longer have left and right unequal length runners. We straightened up the valve angles to move away from the factory bath tub chambers and to a smaller more efficient combustion