I agree with Martyn, higher tyre pressure is good for stability - a bit more in the front end.
My -99 4/4 went from unpleasantly unstable to very stable when I raised tyre pressure to 28 in the rear and 26 in front as recommended by a very experienced Brittish 'Morgan person'. FYI my car is fitted with adjustable AVO's in the rear and the Suplex/Bilstein kit in front.

P.S. I should add that I have no previous personal experience of 'light weight cars' like Morgan, other than 2CV that is...

Last edited by Lecat; 28/01/14 04:33 PM.
-99 4/4, 1.8 Zetec, Indigo Blue, 2-seat, Suplex RS
-04 Citroen Pluriel, 1.6 Sensodrive, Met Orange