if you get a buck made like that you could fab your own tank from cold rolled sheet, fab some end caps and have a shop weld it up for you and do a pressure test. install a few baffles or something to keep the fuel where you need it or grab a fuel system from a scrap tank that has the "well" for the pump to sit in and factor that in along with the flange for the sending unit/pump. or go with a frame mounted pump.
you could swap your explorer 8.8 for a mustang 8.8 for a centered center section. somebody would be tickled to buy your old one set up for the task force, maybe.
found this info on the net, if that interests you.
79-93 Mustangs use a 57 inch wide rear axle. 94-98 Mustangs use a 58.5 inch wide rear axle. 99 and newer Mustangs use a 59 7/8 inch wide rear axle. Lincoln Mark7 LSC, SVO Mustang and Fox Body Saleens use a 59.5 inch wide rear axle.
https://lmr.com/products/mustang-axle-guide
just a few ideas to ponder and confuse the heck outta ya, lol.