'81 280ZX 2+2 L28,5spd,R200 into my '74 260z

Ed is correct the R-200 is a stronger diff . but the 180 is plenty strong . I was under the impression that you were after different gearing of the R-200. As was stated keep the diff. for any future project as well as the half shafts . I would keep any part that you can use on the 240 that is good.