Thanks. In view of the evil vibration at 144°, I suspect the true setting should be 107°. I'll see if I can con a younger & more supple bloke to check the flange angles, although they looked OK to me using a digital spirit level. Squinting at close range while lying on my back gave me rather unpleasant vertigo. It'll probably take until next year to find a company in France to re-balance the prop, very few front engine rear drive cars over here.
