Why? You are going to get better performance out of the dual SU's, they are easier to rebuild and they are twice as cool. Go over to www.311s.org and look at the top of the page at the wikki. There is an excellent carb section. You should also look at Ztherapy's website. If you have the money, do two things to your roadster. Get Ztherapy carbs and get a Dave Brisco electronic dizzy. Your car will run like it was meant to. At forty years old now, you can pretty much be sure that both the carbs and dizzy need some attention.