I need some help
 

Hi. I would like to know if it would be a bad idea to put a 1998 4.6 liter romeo engine from a crown Victoria into my 2003 heritage edition pickup.
I found one locally that is low mileage and a good price.
Would this be a difficult swap. What changes would I need to make to make this work.
I'm retired and almost 70 years old, but still don't mind working on my cars and trucks.
Thanks for your advice.
I can find a 2003 engine for my truck. But the price is almost double.