[Zed7]

Welcome.
If it is closed with a ball on one then it should be closed with a ball on all of them. If I’m seeing the picture right. I’d plug it.
But is that hole above the fuel level once the floats shut off the fuel?
Your floats are adjusted and assembled correctly?

 

[Zed7]

I believe, while bench testing, you can attach a hose to the carb inlet and use a Mity Vac on hose with the carbs upside down to see if the valves are sealing.
If the seats and needles are good then the only answer is float height. Either maladjusted or they are too heavy because of leak. There’s no other way for gas to get into the carbs except through those inlet valves.
Is the main fuel hose from the tank connected to the proper tee fitting on the carbs? I know that sounds like an insulting question but it is not meant to be.

Also, those rubber tubes are vent tubes and they are meant to be mounted above the carburetors. There’s grooves or clips for them.

 

[Zed7]

Yes for sure, its not first time to adjusting it, i use service manual, i make a degree like is on service manual and make it on 17mm but its overflow even if i put it all the way down to close it when little gas come in but it owerflov, and when i try to close it with fingers like stimulate the presure on floats and make presure on hose with mouth it close it good no leaking air, even if i make vacum it stay...But when i put it on gas its starting to overflow...

Yeah, gas seems to get through everything. Maybe the floats are somehow binding up in their mounts after assembly?

 

[Zed7]

If floats no longer float due to plastic degradation they can fill with fuel and become "heavier"

You would actually see the gas inside the float upon removal if they were compromised somehow, which I doubt. But I think despite his new float needles, they just aren’t sealing well. It doesn’t take much. Just a little crap on the surface of the valve seat will do it. That and a leaky petcock.