[suicideneil]

1) search > "emaxx center diff" = , this is a VERY common question, though it helps to know if you mean a centerdiff driveunit, or just a center diff to go inside the tranny...

http://www.rc-monster.com/forum/showthread.php?t=20780
http://www.rc-monster.com/forum/showthread.php?t=25581 (same principle)
http://www.rc-monster.com/forum/showthread.php?t=10233
http://www.rc-monster.com/forum/showthread.php?t=15663 ( different approach )
http://www.rc-monster.com/forum/showthread.php?t=25191
http://www.rc-monster.com/forum/showthread.php?t=19881 ( long project )
http://www.rc-monster.com/forum/showthread.php?t=18366
http://www.rc-monster.com/forum/showthread.php?t=11190
http://www.rc-monster.com/forum/showthread.php?t=9731 (epic )
http://www.rc-monster.com/forum/showthread.php?t=15165
http://www.rc-monster.com/forum/showthread.php?t=2332 ( same principle )
http://www.rc-monster.com/forum/showthread.php?t=12365
http://www.rc-monster.com/forum/showthread.php?t=15165

2) Since a centerdiff unit is NOTHING like the traditional transmission & motor mount, you have no option but to use either a homemade mount or Mike's centerdiff unit & mount ( when he gets around to making some more )..