If you tie the vent into the top part of the waste and overflow (tub drain), then your bathroom will smell pretty bad.
I am installing a new bathtub and was wondering if I could tie the vent pipe into the side of the tub overflow pipe. I know this is hard to explain, but I am running the new tub into a different drain and need to make a new vent connection. Thanks for your help.
No way do you even want to consider doing it. It MUST be connected to the drain line AFTER the trap. The overflow pipe is ahead of the trap.