Edelbrock Manifold RPM Air Gap Oldsmobile 455Utilizing 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. This Part Fits: Year Make Model Submodel 1972 1973 Buick Centurion Base 1973 1974 Buick Century Base 1977 Buick Century Custom 1973 1974 Buick Century Luxus 1972 1974,1976 1979 Buick Electra 225 1972 1974 Buick Electra