Old cast aluminum deep pan capacity

That sucker is deep. It’s either 4 quart or more for a 727, or it was intended for a 518/46R series overdrive with 2.5-3 quarts over stock. But like RustyRatRod said, it does not matter, just fill it until the stock dipstick reads correctly, if it’s a stock correct style dipstick and tube.

Is there and extension in there for the filter? Does not matter for the full, but I am curious.