Sending unit vent vs height of tank?

[Stomis]

So I had a tank unit sitting around from the street truck. It was for a 94 TBI pickup. I threw it in the burban tank for the S10 project and it was about 1.5in too tall. So I cut return line that mounts the the float and the and the pump and shortened it 1.75in and cut the feed tube back. Fits in the tank perfect but now Im curious if I need to cut the fill vent down too.

Am I correct in thinking that what ever height that tube is in the tank is when the gas pump is going to pump? If so I should trim that tube back to say about 1.5 inches below the bottom of the sender top?

 

[K85 Octane]

have no idea, would only assume the higher the vent tube the better lol