tank sending unit question

[naphtali5725]

I have an 86 C10 with dual tanks. they both have three outlets on them.
I am buying new tanks, and want to get new sending units too.
I want to run a holley or other electric fuel pump with a regulator.
I plan on keeping the original dual tank tank switch valve, and switch on the dash.

Should I get tank sending units with just 2 outlets? or do I get the ones with 3 outlets?

I'm a bit confused on this one, since I have looked at a few holley electric pumps, and I don't see return lines on them, unless I'm looking at the wrong ones.

any suggestions? thanks guys