[undy]

It depends on how exotic you want to go...

The LS7 (I know it's a chevy) is a 427 small block and it twists 7 grand all day long from the factory, for over 100K miles. Use the same technology and your windsor can do the same. The LS7 uses titanium rods, titanium intake valves, sodium filled exhaust valves, light weight pistons along with a host of other light weight componants. The point is, a 427 Windsor stroker has the "potential" for a reliable 7K+ RPM capability.