The gauge wire on the pumps is probably 12. Ok for the short distance. I soldered the new wires directly to it and covered with heatshrink. I also offset the joints so they cant touch even if no heatshrink was there, which is good practice anyway. Seems fine with the fuel, as I had the lid off recently to replace the rubber gasket around the lid as it was pretty shagged, but not sure how e85 would go with it. I have been thinking about how I approached this and want to change it as I don't think it's the best way. I am worried about capillary action or the pressure in the tanking forcing fuel up through the inside of the wire out of the tank. I have come up with a new plan that solves that issue, and also removes the need for the plug. Its using a special Bolt/stud combo I found. If you can't get it, use threaded rod and a nut, but you would have to silver solder the nut to the rod to stop the gap in the thread letting out vapour/fuel. I have attached a couple of pictures to show what I mean. Only involves drilling a couple of holes through the lid.
That bolt stud thing is one piece, pretty weird!
I was asked via pm but figured i will answer here regarding fitting the pump into the standard cradle.
I didnt take photos, but it fits in the Stagea cradle with a little cutting, and is secured in place with some decent cable ties, which loop through some holes I drilled in the side of the cradle. Even managed to clip the lid back on. Pick up is as low as it was original, and I have run the tank to below the E on the gauge no worries!
BIG TIP
Buy a new rubber gasket for the lid. I paid around 30 from nissan for it. Yours will swell up and not fit back in.