This will be my next major mod. The Constant Velocity or CV carb as discussed in the "Best Carb" thread is agreed upon by many, to be the most effecient carburator and therefore, I will be swapping out my Bendix for a CV and retain the Bendix as a backup. For anyone else considering this mod, here is the link to the boys at Sportster.org who just so happened to do this on a 1975 XLCH just like mine.
http://www.sportster.org/tech/carb/cv-fe.shtml This mod is supposed to improve performance and effeciency by as much as 30% over butterfly carbs like the Bendix and S&S Super E. We will see. I will post my results as soon as I complete the mod and field tested it.