Quote:

my best throttle response speed with the CVK carbs was drilled 3mm and the stock spring and the shrouding for the atmosphere side of the diaphragm removed (sort of like porting the carb).



As a follow-up, was that with the 865 or 904? If it was the 904, the 904 big bore kit should have increased the vacuum demand on the stock CV carbs by at least a little bit all by itself, all other things equal, eh?

By "removing the shrouding" do you mean the shroud at 12 o'clock near the mouth of the inlet, upstream of the slide?