Here's an interesting eBay listing. Actually two. There is an active listing for a 1972 455 HO YE engine and transmission. Stated to be running and complete, sort of hinted that carb and intake/exhaust manifolds are correct.
If you search the sellers completed listings you'll find that he was offerring to sell last month what is represented as a 1971 Formula 455 HO sold new out of Royal Pontiac. He states that car is a basket case due to rust and that basically he is selling the engine and drivetrain, but you can have the whole car.
Here's the two links. Might be an interesting project for someone if it checks out. Located in Delaware.
Completed Listing
http://www.ebay.com/itm/455-ho-ponti...p2047675.l2557
Active Listing for Engine
http://www.ebay.com/itm/Pontiac-ho-4...item20ea91ca01