This is the drawing of the new radiator.
Chris of Hartgers Race Radiators told me that a 7 cm thick radiator is most efficient for my car. Thicker then that will only improve cooling capacity marginally. The shroud will improve cooling capacity with about 30%.Thicker hoses to and from the engine/waterpump improve flow and less corners also. Together with a better fan cooling capacity is almost doubled, while radiator can still be in the same place.