cj5 fender flares

I imported a set of Crown fender flares for my 1977 CJ5 from Morris4x4centre On the invoice and on the box it shows fender flares for CJ5, CJ6 and CJ7 Front ones fit perfectly BUT the rear flares do not fit my CJ5, they are way to long. Do one get different wheel arch sizes on a CJ5 or why...