Sorry man its built into the trans.  But lentech sells a valve body that make it go 1-2-3 and you flip a switch for over-drive.
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THE SLO PONY
1992 Ford Mustand LX.  2.3 liter four-banger, auto. Future mods: V-8 swap.  

  Fly it loud, Fly it proud!!!
If it ain't broke, you ain't tryin hard enough