Kenlowe are crap these days. The stat I use clips externally to the top hose so no question of leaks. The best fans are the ones from a breaker that are OEM for a car with a similar size engine.Thanks for the replies guys. I'm not a fan of electric fans - fitted a kenlow set to my V8 some years ago and had endless problems sealing the sensor. I tested the thermostat before fitting it and seemed OK. The engine is running cool - I can feel some warmth in the top rad hose, so I think the gauge is OK. I fitted a new radiator and stat after overheating problems with the old head. I guess I'll leave well alone.
Keep it standard, simple and nothing much to go wrong.
Definitely need the fan if it ends up under load, ie 2nd gear for 20 mins in hot sunshine going up side of a mountain track! was glad mine had one