Re: Oil Geyser
Yeah, eight quarts sounds like about 1.5 to 2 quarts too many. I'd suggst draining the oil, replace the filter, and add six quarts. Then see where that is on your dipstick. Should be real close to FULL. If it's off the dipstick altogether at that point, you need a new/different dipstick that you can rely on.
On the other hand... I wonder if your drain passages in your heads are all open. Do you have a reliable oil pressure reading? If so, what is it? If you have low oil pressure with this problem of too much oil on the top end, then perhaps some of the openings in the heads which allow the oil to drain back to the sump are clogged. To check this would be as simple as removing the valve covers.
Just a couple of thoughts.