to save you some time and money (i was the ginny pig for this) DO NOT buy the cen diffs with the metal case. they are totaly different then the ones needed. they use larger bearings, a different ring gear, and the inner gears are not held in by pins there held in by e-clips.
DO NOT GET THIS ONE
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=260343745616&ssPageName=STRK:MEWN:IT&ih=016
GET THIS ONE.....
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=260343744139&ssPageName=STRK:MEWN:IT&ih=016
this is what the first one looks like inside (THE WRONG ONE)
you can see the larger bearings. the inner race is a larger size so you can not use the hpi bearing.
http://i41.tinypic.com/5umlh2.jpg
DO NOT GET THIS ONE
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=260343745616&ssPageName=STRK:MEWN:IT&ih=016
GET THIS ONE.....
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=260343744139&ssPageName=STRK:MEWN:IT&ih=016
this is what the first one looks like inside (THE WRONG ONE)
you can see the larger bearings. the inner race is a larger size so you can not use the hpi bearing.
http://i41.tinypic.com/5umlh2.jpg