1996 Cougar 3.8 one year only engine???

[bodyman61]

Hello,
I just purchased a super clean 1996 cougar with a 3.8 v6. I got it for a decent price because although it only has 50,000 miles, it has a rod/main bearing knock.
My intention was to purchase a used engine and install it in this car. I now find out that this 3.8 was a one year only engine and I must purchase another 1996 engine for it.
What is the difference other than ignition from the 1996 3.8 vs any other year and can I use a different year engine by using parts off of the 96 engine?
Thanks for your help.
Paul