2005 Chrysler town and country 3.8l
 

Can you swap a 2005 Chrysler town and country 3.8 out with a 2004 Chrysler town and country 3.3??

Yes it will physically fit, however, you will possibly run into ecu issues, in that you may have to have the 3.8 ecu remapped (although I'm not sure if this is possible) or fit the unit from the 3.3. Otherwise you may find you run into fuel metering problems.

However, there's also final drive ratios to consider. I don't know if they differ between the 3.3 and 3.8.