I just came across a manifold that looked the same to my eye, was described as a C-Body HP manifold for the driver's side, and was a 408, not a 409. Just curious if it was the wrong casting or the wrong description.
Numbers are easily confused on old manifolds if they are pretty rusted or not cleaned really well .. incl mistaking an 9 for an 8
Or the 408 he's quoting may be the part number as opposed to the casting number which most people reference. Actually polara66 once told me that the part numbers he's looked up were frequently 1 digit different than casting numbers (I think I'm recalling that correctly).