Q: Can we put a 2000 town and country 3.3 v6 into a 2000 dodge caravan that was a 4 cylinder

The alteration in weight will require suspension/alignment modifications that will have to be engineered. The carryover of the PCM and all controls must be comprehensive but even if you can get it to work, you might run into issues using the car legally. Even prior to doing this work, you would have to confirm that the "new" vehicle configuration is certifiable insofar as Federal emissions law. Please see the relevant Federal EPA Engine Swap Guidance Document. California, and a few other jurisdictions, have additional requirements and, in the case of California, these are published in the California Engine Change Guidelines. Unless you have very sophisticated test equipment and a thorough understanding of what is allowed in an engine swap, you are much better off keeping the stock engine and, if need be, simply rebuilding it. Indeed, that is the advice stated up front on the California guidelines document. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.