I've got one off a '78 440 that I got from a guy. The carb got rained on, and the butterflies don't move. You can soak it? Or use it just for parts. You can have it for $5 and the cost of shipping. PM me if you're interested.
The '72 340 T.Q. from craigslist link above does not have the correct top! This will require different primary jets and will hurt performance since the '72 top was different than the '73 top it has now, David.