That is incorrect. JDM ZC Ecu redlines I believe if memory serves me correctly @ 6800, maybe 7000. (7800rpm at a regular interval would most definatly give that ZC a short lived life, approximatly a few hours if your lucky!), The US 1.6 Integra Ecu should be roughly the same or a few hundred rpm less, Hence your 6500 rpm redline. The engine should run smoother at idle as well if you attain a JDM ZC Ecu. The only downfall I found to the Jap Spec Ecu's are the speed governors, generally hit between 110 & 120mph. But there are trade secrets to getting around those.

Also keep in mind that RPM's are a range of the powerband and an essential component of keeping your engine together is the Redline ignition cut or fuel cut in some vehicles. Just because an engine revs higher doesn't neccessarily mean it's making power that high in the band. Most honda engines in stock form tend to start losing HP and torque at their peak RPMs anyhow. The only way to successfully squeeze more juice out of them and use that upper RPM range is to change the Cam profiles accordingly and free up the breathing of the engine. Even dialing in Cam timing w/ adjustable gears will allow a lil more on top end as well. A lil' helpful advice I hope.