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Set toe control (Y)to 9.22 instead of 9.17. See what .050" of rack height can do!
A rack at 10.07 (toe control (Z) or 20.14" overall!!) with a toe control (Y) of 9.28 will vary only .011" from -1" to +3". A rack at 11.07 (22.14" overall - 4" longer!) with a toe control 9.34 will vary only .021" from -1" to +3" of wheel travel.
Shorten the rack?? Many times why bother unless there is interference with something else as long as the #'s agree. How much is too much? I do not know if you can feel less that .060" IMHO.
Also, the loaded wheel should always move toward toe in under bump/roll. This means a rack that is at ideal height or lower with front steer or higher with rear steer.
Vertical height of the rack is the MOST important.
All numbers generated using your suspension points in Wishbone (THANK YOU Mr. McDERMOTT)
JMR

Thanks for your input. You have pointed me in the right direction.

Been working on the steering rack. Here it is after cutting.

End of shaft, waiting to be tapped.
It takes a M17x1.0 I think.

Here's the welded housing. I'll clean it up and paint it later.

Rod-
The rack is looking good. I believe inner tie rod end thread is a 16 mm X 1.0
Roy

Having just gone through this, I can confirm the ends of the rack are M17 x 1.0. See this thread: viewtopic.php?f=5&t=11713

Yes, I had looked at that thread. The Moog photo was incorrect, but the specs at the bottom of the page did show m17x1.0.

If you can, use a tap that rolls the threads instead of cutting them. Doing so lessens the risk of stress cracks and results in a stronger assembly. However, I have no idea if roll taps are available in that size...

I hope you have a large CNC machine to run a 17 x 1.0 roll tap. I can't imagine the kinds of forces involved. I'd reckon it will be pretty tough to keep straight by hand running a standard tap that large with such a close thread spacing.

- Does anybody know whether the factory Mazda threads are actually rolled or just cut?

These holes will have to be plugged.Here's the shortened rack with the removed parts. A little over 6 inches removed.

Back at the shop(basement), I wanted to see how the shortened rack would fit.
Looks like it will fit just fine.
I'll have to figure out a mounting system. The lumber ones probably won't last long.

According to my Wishbone numbers, my rack needs to be about 9.19inches from the ground. Here it sits just under 9 inches. I plan to make the mount about .25 inch below the designed height, and use shims to fine-tune, giving some leeway in both directions.

I also wanted to check the space between the steering shaft and the forward FU tube. It looks like there isn't a problem.

Photos of FU tube and shaft.