Utilizing the proven short runner tunnel-ram style, both of these manifolds provide the next step up in performance for LT1 and LT4 owners. These are both direct stock replacements for OEM equipment with all required emissions features. Edelbrock S/B Chevy RPM Air-Gap Manifold Edelbrock Performer EGR Top Intake Manifold V6. Chevrolet:Small-Block Gen I:262 (4.3L)-400 (6.6L)