This intake #3844463 was used on all early 1963 Chevrolet 400hp engines with the power brake option only. In mid year of '63, production switched over and used this intake for all 400hp 409 application up to the end in 1965. The Carter AFB 4bbl carburetor is the correct one for this intake. The carburetor does not come with intake, can be purchased separately call 407-886-1963 for quote. All early non power brake cars received #3814678 intake.