I just found on the net that the steering shaft adjust by the plastic pins that go threw it. You can get little plastic bolts to put back in so it will still collapse in an impact. Going from manual to power you just need the end to fit the power or manual steering box. The shaft will work on ether. I searched for a long time to find a power shat to change mine over CUDA JAS hooked me up with his spare. At the time I did not know they would adjust to fit ether one. This winter mine will be go power steering. So we need to spread the word on the shaft.
While I will agree that you can pull the main shaft apart and adjust the legnth to match your need, I have been advised on several occasions by more than one knowledgeble person, that it is not advisable to lengthen the shaft in order to convert from power to standard. If you do, the two halves of the shaft will only have a minimal amount of overlap. The shaft can't go anywhere once installed, buy it will lose some strength in the shaft. Once you see the main shaft out of the column this becomes more clear.
I am just not comfortable doing that, so I am still looking for a good standard main shaft.
I am not sure if you can shorten the shaft when going from standard to power. There do seem to be a number of power columns availabel for a reasonable price, so it should be realtivly easy to find the correct parts.
If you need a copy of the deatiled rebuild procedures feel free to PM me your email and I will send you a copy.
Jason