If you opt to buy the Nemesis Diff Upgrade which would require the upright braces as well.. Here are the links to Ebay units which are usually the most cost effective way of converting

[link=http://cgi.ebay.com/CEN-NEMESIS-Front-or-Rear-Differential-Gearbox-New-Diff_W0QQitemZ190098112313QQcategoryZ34063QQssPage NameZWDVWQQrdZ1QQcmdZViewItem]Nemesis Diff From Ebay[/link]

If you dont have the GST you will need these:
[link=http://cgi.ebay.com/CEN-NEMESIS-Bulkhead-Set-New-GS011-Bulk-Heads_W0QQitemZ190098112306QQcategoryZ34063QQrdZ1Q QcmdZViewItem]Nemesis Bulkhead Braces Are The Same As The GST Version[/link]

[link=http://www.headrushhobbies.com/estore_dtl.aspx?pid=229&catn=Genesis/Nem%20Upgrade]Or You Could Pay The Extra And Get It All At Once Here[/link]

There are even Heavy duty Outputs for the Nemesis Diffs Found [link=http://www.customrccars.com/product_temp_trial.asp?id=1668&cat=21&custom=0]Here for $30.00[/link] but you will need the Nemesis Diffs for this upgrade

Hope this helps,,,good luck