That is the same manifold my 1971 318 2 barrel had when I got it, and uses the small Carter BBD. I believe it is a 1967-1972 318 manifold, but I know they also made dual planes at this time. I'm not sure if it's original to my car, and it's out at my storage place but I'll check the numbers tomorrow. Seems like there was one from a 1972 duster for sale a while back. I've seen some information before that if running in roundy racing in the 2 barrel iron intake stock lift rules classes that it's the manifold to use when using 318 heads. I often wonder if Holley used this intake as the starting pattern for the Street Dominator intake.
