Generation IV Internal Engine - How high can you safely rev a 325 CI Bottom End on a daylie drive basis ?

I saw (LC9) spec sheets that say the stock rev limiter kicks in at about 6200 RPM.
Do you see any problems taking it to 6500 by replacing the springs (and Valves ? ) with LS6/LS2 counterparts. Since it has smaller (lighter?) pistons than the 5.7l or even the 6.0l ( the 7.0l with titanium connecting rods does not count ) it can go even a bit higher. Can it?

You should have no problem going to 6500. I probably would put the Z06 yellow springs on it though. Yes the 7.0 can go higher which the heads allow it by having the flow and being able to build power to 7k.Don't change the valve for the ls6 ones. No need at 6500.

What about the retainers (and other stuff)? This suggestion popt up on an Nissan NSX board (LS1 Swap) during a search for Revlimit vs Fuelshutoff vs Maximum Shift RPM.