Thanks for all the interest and info supplied. The reason I was going with an electric fan was because the front end had a terminal meeting with a Commodore some 17 years ago and the fan and cowling was unserviceable.....along with some other parts. The water pump is new and the V8 alloy rad was the cheapest option. The radiator is 'insulated' from the metal support via rubber and non metallic washers so I am hoping to avoid any electrolysis. Either way is an overflow bottle a necessity ? Once again thanks for all the interest and replies. Being in Perth it needs to be tip top. Will only be cruising with not too many burn outs