I replaced the adjustable Kenlowe thermoswitch by a fixed thermostatic switch. Radiator on @ 88°C - off @ 83°C. The switch comes from a Volvo 360 and it's metric screw is M14 x 1.5. The copper T-shaped fitting comes with a tube diameter of 32 mm (2000cc engine needs min. 35 mm). It's mounted in the lower radiator hose between the radiator and the water pump. Customized T-fittings are available at Schweizer-Motorsport.