If I remember correctly, the only thing you would be swapping out when going to the JDM SR20DE would be just the block and head. To retain the EGR, you would use the USDM intake manifold (assuming high-port) and USDM exhaust manifold. Everything else is plug and play and you can still use the USDM ECU. There really is no gain to using the JDM ECU unless you want a speed limiter and a car that spews quite a bit of emissions. That's where a JWT ECU comes in.
Umm... I would like to have a car that passes smog with flying colors, unless it's a trailered race car or something. Without the EGR, the motor spews out more NOx emissions and there is no power to be gained by removal of the EGR.
The USDM and JDM high-port intake manifolds are pretty much the same with the exception of the EGR on the USDM manifold. You more than likely would lose power using the stock USDM exhaust manifold vs. the JDM manifold, but why bother with that? Get a Hotshot header or something.
What so hard about swapping manifolds? Besides I read somewhere that Andreas found that US cars (or a certain car in particular) actually LOSE (or lost power) because it did not have a EGR.
