I emailed Cardone to ask them and below is the reply I received. Looks like Cardone part 22-2000 is in fact built to SPR ZM specs with the upgraded torsion bars.
My original email:
Dear Sir/Ma'am, I am inquiring about the differences between two of your remanufactured steering racks for Ford Mustangs. I am looking for a steering rack for my 98 mustang cobra. I noticed that there are two part numbers listed 22-2000 (production spec SPR-ZM) and 22-238 (production spec SPR-ZK). I was wondering what are the differences in the specifications of these two racks? Are different parts used to remanufacture these racks to spec? Thank you very much for your time.
Cardone's 1st reply:
Adam, thank you for your e-mail. The difference with these two part numbers is:
22-238 - Over all length - 48 1/2"
2 1/2 turns lock to lock
22-2000 - Over all length 48 3/8'
turns lock to lock - 2 3/16"
My second email:
Thank you for the quick reply. From my research I understand that the cobra racks (22-2000) have upgraded t-bars in comparison to the other ford mustang racks. Does Cardone use cobra spec t-bars for the rebuild? Thank you for your time.
Cardone's 2nd reply:
Yes, the 22-2000 has a torsion bar that is 0.230" diameter compared to the 22238 which has a 0.212" .
Now, we also have a conversion in the system for the 22-2000 which takes a 22-233 and convert it to 22-2000.
The spool valve on the 22-233 has the smaller diameter torsion bar. That is telling me that we can not assure that the unit that you buy will have the larger torsion bar.
The torque on all of these racks (233, 238 and 2000) is close enough that you will most likely will not notice it.
The rack travel in the 22-238 is about 0.500" more than the 22-2000 which tells me that if you install a 22238 on a 222000 application the wheel will most likely rub in the wheel well.