This manifold is part of the Weiand Nostalgia Series of intake manifolds. Weiand Nostalgia Series intake manifolds are made using the original tooling, and may have minor appearance imperfections that do not affect the functionality of the part. These minor blemishes are a natural part of the casting process when using the original sand casting tooling. Weiand Nostalgia series intakes are proudly cast and machined in the USA. We support all areas of the vintage, show, and nostalgia car hobby, and want to continue to produce these lower volume manifolds using the original tools. There is no need to search for that vintage intake at swap meets or on the internet when you can buy the real deal new from Weiand! ** Square bore carburetors may require plate P/N 9006 to seal properly. Rotary A/C compressor will not clear on 1978 and later applications. The water cross over has 3/4 in. NPT x 1; 3/8 in. NPT x 2; 1/8 in. NPT x 1. The Manifold also has a 3/8 in. NPT Vacuum Port.