Tuning 33mm smoothbores

Since the carb manifolds do-not have vacume ports to tune the 33's can you drill,tap the intake side of the head like you do for nitrous?

Don't see a reason why you couldn't drill/tap intake runners. I have installed vacuum spigots from an old set of carb holders into a set of larger carb holders. It is kind of a pain to get them out of the old rubber but it can be done. If you drill/tap, you will have to use adapters to do the sync but if you modify the rubber carb holder, you can just shove the hoses from the manometer onto the vacuum fittings you installed.

thanks.