Just looked at the name of the forum and ... Buick made 400 cubic inch engines ? Wich car had those ? Max
1967 GS400 for example, or 1968 GS400 and Sportswagon400. Or 1969 GS400 and option on the Sportswagon and LeSabre But with bore and stroke of 4.04 x 3.90 it was almost exactly 401 CI, the General Motors Engineering Policy Committee didn't allow displacement over 400 CI in midsize cars, so it was named the 400
Actually, with a bore and stroke of 4.04" x 3.90", the 400 really does displace 400 cubic inches. You're probably thinking of the 401 Nailhead, which had to be called a 400 in the Skylarks.
Sorry, I also calculated what the bore and stroke 400 CI is and typed those figures. Bore and stroke for the GS400 engine was 4.1875 x 3.640, thanks for the maths
