That axle has a 36.5" spring pad width and was used by several companies over the years to make vans 4wd but they usually put the shackle up front like the F series since it was easier. Not the best setup, especially for ride quality. A reversed shackle is better and there are a lot of variables, spring length and shackle placement will be the toughest part.
02 E350 7.3 (V4)
05 E350 V10 (V7)
17 Focus RS,90 SHO,49 Willy CJ2A