The factory parts books aren't much help, are they? The ones for '63-'65 and '66-'68 show the numbers for pretty much everything else. The sleeves Bernhard mentioned are listed for '66-'67 650SS in one parts list, and for 88ss and 650 in another. They are part no. 23864. The manifold is shown in Plate A as item number 27 in the '63-'65 parts list, but does not show up in the associated list of parts. That's the same plate that Andover shows in their parts diagrams, and they also don't have a listing for the manifold.
However, I found a couple of part numbers in earlier ('61-'62) lists that show part numbers for the manifold. The manifold mentioned above as A27 is listed as part number 22757 and used on models 88 and 99, Std. and De Luxe. There is also a supplement to that list for models 88ss, 99ss, and 650ss that lists an intake manifold part number 23739 as used on '61 88ss and '61/'62 99ss.
My '62 Atlas (titled as '63) came with a 2-1 manifold and a 389/87 Monoblock. I always assumed this was original kit. I read the casting number as X23356. Not for sale, someday soon the head will come back from the menders.
Ok yous guys,
that’s what I have been looking for,
have brought in RGM manifold and it looks nice but not like the original,
thanks for P/N and info and all those great pics. Now if any of you want to part from that manifold I would buy it from you, so just let me know