I did this conversion several years ago but have sold the converter since.
A small caveat regarding the "autofocus":
As Mongo said before, you have to pre-focus the lens. The autofocus range is relatively small, so you have to "lead" the lens manually and then achieve critical focus via the motor in-camera.
I had converted the TC for wildlife photography and long manual lenses, in which it failed me several times.
For this purpose, its just usable when your "target" is within a predefined zone (nest etc.) or moves perpendicular to the lens axis.
If I remember correctly, it was also not defined for lenses greater then 200 mm. The quality was relatively poor.