Well, there are no
oil drain holes in the deck of the block. If there are drains at the top of the head, they are still useless. That means the
oil still has to fill the head under the valve cover in order to get back into the crankcase, via the lifter valley. Other Ford V8s have drain holes in the bottom of the head with
oil return passages through the sides of the block.
Think about this... if you poured oil into the top of the valve cover, and it didn't return into the block until it filled up and reached the upper part of the head, how much oil do you think would be under that valve cover? I'd say WELL over a quart, maybe even close to two. That means at any given time the motor is running, there is at least 3 quarts of oil in the heads. If you had a 7 quart system, you'd have 3 quarts in the head, 1 in the filter, that leaves you with 3 quarts in the pan to feed the motor next time you rev it to 6-7 grand. Sorry, I don't like that idea one bit
.