The basic engine looks to be the same ( Engine Code E ) However they definitely have changed electronics on top of the 03 as compared to the 97 If this is what you want to do I would strip the 97 down to bare bones block and heads and swap everything from the 03 on to the top of it. Making sure that there are no extraneous exhaust or intake ports in the heads that are on the 03 and NOT on the 97 Good Luck
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