I fitted VW transporter 2 speed fans (2 of) to mine because they fit in the standard Jensen mounts, are a tried and tested mod and a vast improvement over the Lucas ones, together with high flow water pump and thermostat . If you also junk the mechanical fuel pump and fit a big output 'lekky one down the back (I've fitted a Facet cube type) then you pretty much solve the hot starting issues, overheating and faltering due to high underbonnet temps.
Julian.