There is no TSM v8.5. (And now it's called 'Spectrum Archive' after v7.1.3, so there won't ever be a TSM v8...)
The CMOD v8.5 patches aren't on the IBM FTP site anymore, but if you can find a README file from v8.5, it'll tell you what the minimum supported versions are.
TSM 5.5 was probably the standard, as it was still extremely popular -- TSM 6.1 marked the transition to DB2 as the internal database, and the migrations were horrendous. I'm still doing them today, because people were so resistant to move up to TSM 6.x.
-JD.