Defender V8 Thermostat change

Recently bought a 3.5 110 and seems to be running hot, temp gauge reads almost on the red at all times and gets up there very quickly. I have just changed the Temp sensor and put a new thermostat. Problem is still there gets very hot and temp gauge is up to the red, top hose is nowhere near as hot as the bottom hose. Thermostat is in with the sprin side towards the engine. Anybody got any ideas, sounds like a circulation problem.
Thanks
Daz

water pump?

I had same problem, changed thermostat, flushed rad, checked fan all with no cure. Then I stuck a second hand temp gauge off flebay on it and now it runs normal.