Posted for "Timothy Ong" <timothy.ong@leadingedgeaircraft.com>:

 Don,
 
 You will probably only be able to keep 6 quarts in the engine without it
dumping the rest.  Try running 5.5-6 quarts on the stick and see if your oil
slick stops.  This is where we have run 407L for the longest time with good
results.
 
 Also, check to make sure your breather is not too far into the slipstream as
this will cause somewhat of a low pressure and assist the oil in coming out.
 
 Regards,
 
 Timothy Ong