Simon,
So far the Mighty Demon has been very well mannered as a street carb for me. If you contact Barry Grant they will be happy to give you a recommendation on which of their carbs would best suit your application. Just have your engine specs ready since they will need to know them to amke the recommendation. They are very good about not recommending too much carb since they want it to work right. Contact details are at
www.barrygrant.com.
Alan