´90s 2.3L power rating difference ¿?

[JoseBronco]

The tech library shows 12 hp difference between 1995 and earlier 2.3L engines and the later ones.

Is it due to a different computer set up or camshaft or ... ???

If were easy to swap the parts I would like to do it.

Thanks in advance.

 

[tcranger]

only thing i can think of is in 1995 computers changed to obd2