from what I have read thus far, our oil pans will hold 6 quarts w/o causing problems with the crank. Maybe some of the experts should chime in on this though.
The trouble with a higher oil level than what Toyota recomends
is that it greatly increases the amount of oil that
the tornado created by the crank turning at 5000 RPM will pick up,
and carry around with it.
This not only robs horse power (kilowatts if your down under),
and does nothing to allow the air bubbles from seperating from the oil before the pump picks it up, but......
It also increases how much oil is carried out the breather by blow by.
The surface speed of the crank, even at 4000 RPM is over 5,000 feet per minute!
That will suck up oil from the pan, if the level is too high.
A crank scraper will do way more good than over filling the crankcase.
Add a windage tray, and it is even better.
Here is a picture of a 7M windage tray I missed in Japan about 5 years ago.
If I knew then how rare some of this stuff was, I would have grabbed it then.
I have not seen one since.......