Here are some pictures of cutting 5.5" off the Miata steering rack and welding the parts back together. This is not the preferred way to to shorten a rack, but it is the cheapest. The quality of the welding is vital to say the least!
These are the shortened pieces:
These are the parts that were removed- I used a cheap compound miter saw with a 10" abrasive blade:
Here is the assembled rack. Part alignment was handled by strapping the parts to angle iron while welding and the end result was pretty good. Everything is straight!