Komatsu -7 and -8 undercarriage

Hi there, does anyone know if a undercarriage from a -8 machine is a direct bolt on to a -7 machine? Or did Komatsu make changes to the undercarriage design? Purpose of the question is that there is wrecked 2016 PC200-8 with a good undercarriage up for sale and I was wondering if it would fit on my PC220-7 (I think I would have to add a couple links as the 220 rail is longer)? Thanks