How about a '65 pickup with an original 409 in it? This one is supposed to be documented as an original COPO ( Central Office Production Order )
http://http://corvaircenter.com/phorum/read.php?1,265088,265986#msg-265986
Not sure how many were made, but they apparently did exist.
It would make sense to make something like that when they were available with 348's. For a '69 truck it would a lot more sense to use a 396, or 454.