.Blue slip for engine swap in nsw, personally never bother unless selling car
.Check out burtons in uk for cable, parts typically arrive within a week
. twin webers and itb's make a lot less vacuum at idle and off idle than a std carb, combined with a bigger cam the vac advance would not work as intended to advance ignition at high vac. I think this is the main reason we never bother to connect it, plus the effort and it has no performance value.

My thoughts: the amount of available vaccuum will be dependent on cam duration - long duration means lower vacuum; short duration means higher vacuum. You can maximise the amount of vacuum available to your brake booster and dizzy by linking the vacuum ports on all four of the carb barrels. Vaccuum advance doesn't help make max power, but it definitely helps with economy. If you are racing flat out around a circuit, you won't need it; if you drive on the street, not having it will result in greater fuel use.