Just a little FYI.

Those are not sheer pins but injection molding holes for a plastic material that was used to support and hold the two shafts together. In an accident the shaft can collapse. If you shorten the shaft it may not collapse in an accident and may cause further injury. If you lengthen it it may not stay together. I doubt this very much since I believe there is plenty of overlap but why risk it.

You have two problems when going from power to manual or vice versa. The shaft length and the size of the spline on the coupler.

Here are a couple of options that safely solve both problems

http://www.flamingriver.com/index.php/products/c0008/s0009/FR1505M

On this page go all the way to the bottom and there is a part ST-SCA.
http://www.jimsautoparts.com/steering_parts.htm

there may be other suppliers to provide parts for this situation.

Hopefully someone will chime in.