An 8-inch Neptune becomes a different cruiser

What tonnage and effect would result if the Neptune-class cruisers were built with 8-inch guns?

A four-triple-turret version might reach about 24,000 tons and should be treated as a distinct heavy cruiser.

The Neptune concept starts as a powerful 6-inch cruiser of about 19,000 tons deep load. An 8-inch version requires choices about gun model, turret design, and number of weapons, including whether to use a turret capable of 70-degree elevation. For a layout of four triple 8-inch turrets, the rough estimate rises to about 24,000 tons. That is a different heavy-cruiser design, so its final size and impact cannot be inferred from the Neptune name alone.