Forgive my stupidity but why rev it past 7,000?
We know we are reaching into the unexplored and we know they can go BANG at 7,500 so why tempt fate? I love the sound of my engine when it's revved but I use 6,500 as a redline as it really doesn't have the goodies inside it too give me anything (apart for the sound) past my redline. It actually pulls harder in a higher gear at (say) 3,500 than it does at 6,500.
When I build my new engine it will be built to go to 7,000 rpm as it will give me more than enough power at those revs.
I think the concept of who can rev the engine the hardest is like who has the most horsepower. What's the point of 800hp when the engine runs like a hairy goat and doesn't produce usefull power until 4,500 rpm and you need a 5,000rpm stally to get it to move. How much fun will that be on the way to work?
Give me an engine that produces power from 2,000rpm to 6,500rpm and my car will be quicker point to point than the monster that can't be driven at anything less than WOT.
I think we're falling into the "Mines bigger than your's" trap.