There's a 45 chop on the HDRCGB forum, which poses some interesting questions.
The engine has twin carbs, and us variously described as "having some race parts in the motor" and "having been built by a well known 1970s chopper builder". It's described as "running well"
Is ths the engine from Ray Leon's bike, Blue Grass Special? That bike had twin carbs and a rather special motor, and it has long since disappeared from view.