The crank counter weights need to spin in air and not oil. Do this little experiment. Wave your hand back and forth in open air. Now do the same thing with your hand under water. This is another reason why it's important not to add too much oil.
This is another one of those things you hear about all the time. On the dyno, there is NO gain untill you go past 6500 RPM. then it does not do much untill 8000 RPM. Usually , just draining some oil out of the pan can make the most differance.( Got to br carefull here)The tray might make more gain in a drag car when it is accelerating. JOE SHERMAN RACING