I don't think there was a 6th gen JDM Si. That engine is more likely from the Integra. Same engine with the exception of cams. I believe USDM cams are two lobe on the intake side, and 3 on the JDM models. You can pop the valve cover off to confirm. Oil pump may be different as well, but I'm not 100% sure on that.

If you want additional power, don't bother. If you just want to swap and have an engine with lower mileage, go for it.

 

thanks you for the info. I was suspecting that it would be the same in regards to power but was not 100% sure because I was hoping that this engine had more potential 😄😄...... Could you could answer this for me... a few days ago I came across a posting I have been trying to find... were some stated a K20 could be converted to a K20A2 are they referring to this base K20A or the type R K20A?

 

They were referring to the base K20A. I wouldn't bother with converting unless you are looking for a project. Base engine lacks the piston oil squirters in the cylinders. They may not be absolutely necessary, but it's good for safety purposes.

 

If you are looking to extend the enjoyment of driving your car put the K20a (econo) engine and drive it. If you are after noticeable power gains, I would look for a K20a2 or a K24a2 before those go up in price anymore. Alot of people are either not aware or not worried, obtaining Honda parts pre 2011 is going to slowly become harder and harder as the popularity increases with the K24 and K20 swap going into everything. Also K24 swaps typically like to use PRB and PRC parts. This year more parts have gone to backorder or discontinued due than ever. Myself and others have started buying back-up parts as often as we can to get ahead of the rising wave. Something to think about.

I have extra many oem parts in storage now. I also just bought a 2008 K24a2 complete longblock for $800. I am after a K20Z3 transmission now.