Thanks for your help guys.
I have the standard SU carbs still in place but with richer needles and no butterfly anti-run valves as yet. I have KN filters and a performance distributer.
I have spoken to Frontline Performance in Steventon and they will take a look at the set-up for me in a couple of weeks time. If unsuccessful I will then try Manor Garage and Abingdon Car Restorations.
I'll keep you posted.