I have a ford explorer 2004 what kind of engine model or year can I swap to fit in my car?

I have a ford explorer 2004 what kind of engine model or year can I swap to fit in my car? - 1

Added (1). my engine is 4.0L and my eight digit number is (K)

Your going to need a transmission that can link up to the new engine it won't be cheap but do you want to make it more powerful or do you just need a new engine and want something different

As long as it physically fits into the engine bay, you can swap any engine you want. Of course extensive modifications would have to be made to make it work but that wasn't your question.