however i thought venting to the stack at that location would create issues from the 2nd floor toilet/closet via pos/neg pressure. i guess the thing im sort of not understanding is the placement of venting in the main stack (generally speaking).
Would i be right in thinking that any pressure from above re discharge would now have no bearing on the kitchen sink if there are two holes (via pipes) regarding the waste hole and the vent because there is no vacuum to be pushed or sucked from the kitchen pipe? becuase there is like a release loop created by the two holes.
hope that made sense!?