Ive actually measured the distance that the crank goes down into the pan and the distance the oil goes up at the full mark and there is a good inch of space between the two. If you also understand that this measurement is only accurate when it isn't running then the distance between the two gets bigger because the oil that is running through the engine is up in the crank,block and head and is returning to the pan. I have run an extra quart in my 65 200 making the oil level about 1/2 inch higher up the stick than full during the summer here in Texas. It helps the engine stay cooler and reduces oil breakdown along with keeping the oil pressure a little higher. I'd leave it in.
Dave
Dave
