Bought a set of carbs from eBay that the seller assured me would fit my 79 CB750F SS. There is a "T" fitting along the fuel rail between #3 and #4 carbs. Should this be capped? Pics for clarity. Also, there's a capped nipple on the throat of #2 carb. Does this supply vacuum for the slides in my carbs? I know, rookie questions, but this is my first foray this deep into a 750. Thanks in advance!