Chrysler Grand Voyager - autobox swop - skullmaster

hi can you guys help.my grand voyager autobox died so i bought a new one my car is a 1997 i didnt want to but anuther 1997 as didnt now how long it would last so bought a box from a 2001 modle and torque connverter put it in but it wont bolt up all the way slight gap between bellhousing and block im hopping it will fit but dont now why it wont hope you can help thanks guys..and gals.