Don't know anything about builder or seller, and while the design is not perfect correct (ie. distributor location) it's pretty amazing.  Apparently he built many, as other engines are for sale also. Looks like it won't come cheap.

http://www.ebay.com/itm/Haagenson-Miniature-Engine-Ford-Y-Block-V8-Overhead-Valve-Dual-Carb-SCTA-NHRA-/370649235550?pt=LH_DefaultDomain_0&hash=item564c6a805e

Ted, Redding, CA