If you're looking at the AIM, UPC 6 Sheet B3, the V8 starters they list on the diagram and in the revision record section are for a base 327. These are the 7320 and 7496 you listed.
If you look at the UPC L48 Sheet A2 "V8 Engine 350 Non-Illustrated Parts", it lists a starting motor, and also tells you to see a parts list or bill of materials for the part number. I don't think this documentation exists any longer. From what I've read, it seems many think the 8338 is correct. In Parts Catalogue No. 731A December 1972 it lists 1108338 as the correct starter for a 67 350, also used in 68 and 69, with the 1108400 being the service part number. http://gmpartswiki.com/getpage?pageid=53513
Looking at all the parts books can get confusing, I've seen instances where it looks like the 1107365 is listed for the 67 350 and 396 but maybe I'm reading it wronghttp://gmpartswiki.com/getpage?pageid=83153
Kurt was asking for information on known factory starters back in March, so there may be a research report in the works.