For awhile I wanted the Edelbrock D66. Its a dual carb manifold for the small block mopar. Later I was informed the D64 and D66 are both for the 273-318. I went with an Offenhauser (Its application is 273-318 as well) cuz its available brand new and its single plane design should still feed a 360 adequetly. Is see for big a small block chivy one can get a dual quad in standard AND Air Gap design.