You will just use the block and head from the 2.3l, use 2.5l intake and exhaust, plus all accessories, i.e. alternator, PS, AC, ect...
Oil pans should be the same.
2.5l used Returnless fuel system so you need to use that intake on the 2.3l, yes it will bolt right on same for exhaust
Computer will adjust and work fine with the 2.3l, it is a MAF(mass air flow) system so can handle small changes in displacement
Put a sticker on the rad support with any info you have for the 2.3l engine, i.e. year, model of vehicle it came from, ect....
This will help you down the road if you need an engine specific part.
I would suggest changing the timing belt and installing a new rear main seal while the 2.3l is out of the vehicle
Last edited by RonD; 08-27-2016 at 04:14 PM.