Reverse flow decreases the temperature of the coolant through the cylinder heads by this amount. The fact that steam rises complicates reverse flow systems and generally makes the 1-2 F reduction in coolant temperature insignificant at best. The flow through each orifice in the head gasket can be determined by measuring the pressure drop across each orifice while coolant is being forced through the engine. Coolant flow has a direct relationship to area and an exponential relationship to pressure. Strategic Flow systems take advantage of the knowledge gained through flow mapping.
Coolant is taken from the highest point thus eliminating the pitfalls of reverse flow systems.
The most important criteria for any radiator is it's surface area. The thickness of the core is increased only after the surface area is maximized. Adding thickness to a radiator does not increase it's efficiency the same extent as surface area, but in no case will additional thickness alone decrease the efficiency. The radiator becomes less efficient as the coolant outlet temperature approaches ambient. Therefore, a low flow rate keeps the coolant in the radiator longer.