I've done a little digging around and found that the earliest Elfin 400 Sports car, frame #661, built for Globe Products in June 1966, was originally supplied with a "Ford Cobra V8" engine, presumably something based upon the Ford / Shelby high-performance Windsor 289ci V8. This Elfin was later transformed into a short nose version and the Ford small-block V8 engine modified by Kevin Drage in 1968 to incorporate specific twin-cam cylinder heads ... I'm sure there's much more to the story to be found, but for the moment here's a period image of the car and more particularly, a period image of the quad-cam engine being dyno tested ...