You doing an electric fan?
FYI I would stay WELL CLEAR of ones like this

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I had a couple of them and they clamp into the top hose. Both the ones I've had have ended up with the thermostat on the end snapping off inside the top radiator hose leaving you with no fan!
These ones are more expensive but are honestly worth it!!!
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Also don't get the cheapest fan... they can look identical but often have poor quality motors!
Mine packed up on the way to an SCUK green laning trip and I had to shell out £80 for a replacement fan