Paul it's not that straight forward, I did some research and talked with various tuners and racers in the USA about the Mustang, they have the same issues though less pronounced due to the weight of the car and also only the GT had a manual box, the ECU being set up for an auto. Some have managed to resolve it and others not, but not cheaply. The situation with the Morgan 3.7 is worse as Ford locked down the ECU and also tied it to the canbus supplied instruments. I talked with a major designer of ECUs in Italy, who supplies a lot of the automotive industry, he said yes it could be overcome but with difficulty.
Adrian
Buggered Off, to a modern none leaky car, heart's still ticking