If you do the heads right, with solid lifters and increased spring rates, wouldn't you be able to raise the rev limit? Or is there some other limitation on these V10's revving past factory?
There is a general fear about letting the V10 rpm higher...
the truth is the factory engine management has not historically been supportive.
Built right, with some basic but good parts, if you precision blueprint and balance the engine, and run an AEM - there is no reason you can't wring that baby to 7000rpm for short bursts on an n/a motor... but I would add an ATI damper and a good oil like Redline
For more insurance at those rpms - you need oiling mods - a dry sump being the ultimate but not necessary if you know what to do.
There is no magic - anyone who tells you the Viper engine can't rpm is probably wrong about other things too.... they can rpm - you just have to do the right things to let it breathe and keep it happy up there - they are no different to any other OHV big engine. The AEM opens up a whole new world. A cheaper alternative may be to get a factory chip reburned for a high rpm tune... but the dyno time setting up to get it spot on won't be that cheap....
Get the heads flowing around 300cfm with great velocity, add a FAST action solid cam with at least 250 degrees at 0.050" (keep intake advertised duration @ 0.020 in the high 280's for street), and you will move mountains on a good build up. Keep valve springs under 160lb on the seat and under 420lb open, and use titanium retainers with lighter high flow valves.
If you can afford it, run Schubeck ceramic lifters (they'll last longer than the engine and allow aggressive opening ramps).... a little outlaw secret