Smoran - the shortened shaft allows room for mounting the power steering box. The CPP site also has a tech page, with step-by-step instructions for this installation, which allows you to use the more or less stock (now shortened) column with the power steering assist. Check this out:
http://www.classicperform.com/tech_articles/567-605-power-steering/tri-five-605.htm
Good luck.
http://www.classicperform.com/tech_articles/567-605-power-steering/tri-five-605.htm
Good luck.