Not to hijack, but I'd love to get something to give me some more range. I've never looked at anything other than a standard capacity aft tank; are there any other modifications you have to make when installing a larger tank?
The F26E tank comes with everything required, longer bolts and spacers to mount it, the extensions for the fuel pickup and return, etc. Personally I bought some compression fittings (5/16" and 3/8" IIRC) instead of brazing the extensions, and I used brake line bent how I want and cut at an angle towards the bottom to ensure it will get fuel all the way to the bottom. I did not use any sort of filter on the end of it as I'd prefer my failure points to not require dropping a tank. I also used a coat hanger to bend up a new float arm and calibrated it so it reads accurately from full to empty. Spectra instructions just lower the existing sender without modifying the arm, so it would read full from full to half tank and then drop from there. Aside from the sender/pickup modifications it's a drop in deal and comes with mounting hardware, new O ring and lock ring.
My truck had the rear tank skid plate so I picked up some rear tank straps at Advance along with some all thread and nuts. Mounted the tank using straps and then mounted the skid plate below that, so there's a gap however thick a 3/8" nut is to keep from holding water/mud/whatever right against the tank. I also primed and painted the tank and straps, and took my old skid plates to bare metal and primed and painted those too. Should keep the rust at bay and easy to hose out that gap whenever washing the truck.
I also did the tank vent mod on each tank when I did the big tank in back. it's documented elsewhere but basically drill the rolover valve out and epoxy a nylon elbow in it, run 5/8" hose to a NPT nipple high on the filler neck. I had trouble filling before but now it'll go as fast as the pump does. Worthwhile if you've got your tank out as you need the back tank out or bed off to do that one.