I Have a 2002 Forester S with a bad transmission/differential. I have a rolled 2001 Legacy L with a good transmission/differential. Can I swap the Legacy stuff into the Forester? The numbers on the Legacy are TZ1A4ZCCCA-LM and the numbers for the Forester are TZ1A3ZC3AA-PM. 
  
Do I need to swap over the computer controller thing also (TCM)?  
  
Thanks for any and all information.