Paolo,

Contact Chris Weddle at info@2weddle.com and he will email you all the
info you need. Also, their website is www.2weddle.com and their phone
number is listed there. They are in California (Goleta I think).

I have one coming from them in a week or so. I also went with the 4.57
final drive as I did the math and that one works the best for my needs.
The lower 4 gears are just slightly lower than the 4-speed box but 5th
is what it is all about. Not cheap, but it should last me a long time. I
plan on keeping my Vanagon for quite a while.

Good luck,

Arlen - 4 is not enough.