Light and Heavy Timber Framing Made Easy by Hodgson has some good heavy duty scarf joints illustrated.
The entire book, being now public domain , is available for download here (only to those in the US, I'm afraid.)
Light and Heavy Timber Framing Made Easy Ken,
I will email you the section dealing with scarf joints, since those outside the US can't seem to access the google books version. (at least that was true a couple of years ago)
