Engine ID #'s

could use some help here. Recently I was given an engine that I was told came out of a 90 Model, just like I have. Current motor has almost 300,000 on it and am planning on rebuilding the donated motor and swapping them out. Want to make sure this one will swap in with little effort, but do not know where to look up ID #'s. Number stamped on the donated motor is 53020569 and has NVH above and to the right of it. Any ideas?

This page shows it as being an engine block number for the years 1996-99.
http://www.jeep4.0performance.4mg.com/tech_specs.html

There are a few google hits here:
http://www.google.com/search?hl=en&q=engine+block+number+53020569