Now that I think about it, I can't recall seeing the small outlet that drives the venturi pump on the in-tank fuel pump supplied with the Radix kit. Can anyone confirm whether or not they have this outlet? Don't feel like dropping the tank again just to check that.

Here's a pic of the stock pump:

 

they do have a bigger hole on the bottom then the stock pump.....

 

What about that little outlet tube(the red arrow in the pic) that drives the venturi pump to keep the tub filled?

Does your Walbro pump incorporate some mechanism to keep the tub filled?
Does it differ from the factory pump?