rear axle 8.8" assembly from 94-04 Mustang will it fit a Duster/Demon/Dart sport?

it will fit, but your better off with the explorer 8.8's as they have the 31 spline axles and not the 28's like the mustangs. you just take 3 inches from the drivers side axle tube and run a passenger side axle shaft in its place since its 3 inches shorter than the drivers axle you just removed and fits perfectly. also depending on your area they may be cheaper/easier to find. also i think the mustangs had control arm mounting points cast into the center section of the housing.