1990 2.5L YJ / 1991 2.5L YJ Whats there a difference?

[maxwell30434]

I have a 90' model with the 2.5 . All the upgrades i find online are for a 91' model. Whats the difference. I would like to put a intake on my jeep but the air tube is oval shaped & not round. Any help???

 

[superj]

Wow, you would think that close would be the same. I womder if that is a change over year for the r cylinder engine?