Check out Cycle World Mag, has a nice article on the Triumph Street Tracker created by Mule Motorcycles in Cal. Pollack builds some sweet Flat Trackers for the street, however these are one-off machines that cost upwards of 32K. Literally hand built with mixed/matched componentry. The Street Traker was commissioned by Triumph America Corp. and will travel to all the shows this year. A great piece of work, worthy of masss production in some similar form
Under the heading, "Projects", click on "completed" to see the Triumph. Great pics are shown, including one of a twin head on a valve machine, getting machined for larger seats.