I am glad to say that my car is now running well and showing no signs of overheating. I did have a leak appear around the coolant pump but after retightening the bolts it has now stopped.

For me the moral is that shifting 40 years worth of crud takes more than one go, you have to persist with the flushing unitl you are sure you have cleared it all, including the block and heads.

I recently did a 600 mile trip in the mountains and she ran just great. On one trip I was touching 125 indicated and still plently to go. Not bad for an original 260. The Tiger is surely the best car I have ever owned.