Have now had new 14 inch dual speed one fitted (a friend and I bought one each at LRW Eastnor show for £120. All well but it's an amazing indicator of how little a fan is needed as even in this warm weather, it does not need to switch on in normal road or offroad (pigeon shooing and the like) use- only when tonking along dual carriageway for 10 miles or so at my 1989 T/D 90's maximum "cruising speed" of 60 mph
All seems quieter in the engine department and there must surely be some saving on fuel consumption. There's now loads of space in the engine bay
Thanks to those who gave advice on location - fitted between radiator and engine and pulling air through