PS/2 Proprietary SIMMs
For an explanation of the difference between PS/2 SIMMs and Industry Standard SIMMs, and an extensive list of many part numbers for PS/2 SIMMs, visit Louis Ohland's PS/2 SIMM summary .

Below is a short summary of the IBM PS/2 SIMMs that I have found applicable to PS/2 8580 bus memory adapters.
Size    Speed    Option Numbers      FRU Number         Manufacturing (Visible) Number
1 MB    85ns.    6450603             90X8624       65X6264

2 MB    85ns.    6450604,92G7196     92F0104       65X6249
        80ns.    6450608             92F0103       65X5806

4 MB    80ns.    87F9977,92G7199     92F3337       68X6343
        70ns.    6450128,92G7200     92F0105       71F7010

If you are looking for an IBM source of Marketing part numbers and FRU (Field Replaceable Unit) part numbers snd other details, visit  IBM Memory Cross-Reference and  PS/1 PS/2 PC Memory Reference .