Like the title says.......

After 22 years and 170,000 miles, I need to freshen up the front end on the 98 S70 T5. Everywhere I look for parts it asks if I have an SMI or TRW steering rack. I looked on the web and found that the product plate in the engine bay should tell you what steering rack you have. From the info I found, if the last stamped number of the code is a 4 you have an SMI rack, and if it is a 5 you have a TRW rack. Well, my last number is not a number, but the letter "S" (and yes it is an "S" not a "5" as I compared it to another stamped 5 in other parts of the code).

So.......what steering rack do I have, and is there another way to check since the one I found is not making much sense

 

Well, 65 views and 5 days later, no answers, suggestions, or even a hearty go to hell tells me I need to ask elsewhere