If the crossover has it's original ('71/'72 only) brakes, then yes it should fit.
'71 and '72 shared disc brakes and spindles, the parts are NOT one year only. Even Transporterhaus list them as '71-'72 (not one year only).
The calipers were upgraded (increased in physical size and piston length) for the '73 model year and these are not interchangeable without different spindles (or a caliper mounting kit).