Upgrading to SI 24/24 & Polini Venturi


I got a -69 Sprint with a 177 DR kit,standard Carb and a Simonini right hand exhaust. I'm Thinking about getting the SI 24/24 and the Polini Venturi air intake.What would be a optimal jetting on the Carb with this set up? And would a different exhaust give more power? 

Read somewhere that the standard Sprint Carb casing will be a bit snug with a 24/24,is this correct?