It is not a cheap option, I looked into it at a Classic car show last year. The rep was keen to tell me all about it and explained you have to use a stabiliser or similar once the cooling system has been drained. He also reckoned it was a good idea to replace all the hoses as any leaked become costly.

He reckoned by the time I had bought the stabiliser and coolant I would be looking at over £275 for my Jensen.

Steve