what I would really like to see is how you got the power out through the factory sending unit, and where did you get the pieces that you used to do so?
The connector I used is a Conxall/Switchcraft pn:4182-3SG-300
(mates with Conxall/Switchcraft pn:3182-3PG-3DC). Both are available from Digikey. One pin is used for the sender and the other 2 are for the pump power and ground.
I used fuel tank sealer around the soldered pins and connector flange for added insurance
against leaks.