Fantastic responces guys while in the UK i will have a look at the asymmetrical springs ,
Button , looks like i need to add Seattle to a road trip and see what you are up to .
The reason i am looking at springs is to improve the ride with a more supple suspension and to lift the rear slightly as its settled over the years .
Axle tramp has never been a problem even though i tend to drive like an adolescent hooligan and my car was dynoed at 280 HP at the wheels
Dave