I would keep watching ebay.I was going to use a Street Dominator on my 351c and it is a single plane design (there is one on ebay right now)but I found a Weiand X-celerator #7516 at a local swap meet so I will try that one instead.The guys on the Cleveland forum seem to like the Weiand more than the Street Dominator. http://www.network54.com/Hide/Forum/119419
I see 4 bbl intakes for 2 bbl headed Clevelands on ebay all the time, just keep watching. A 4 bbl port intake will work on two bbl heads, but as hobbyhorse said, there's a port mismatch.