Ke30's had sumitomo callipers, ke55's had girlock.
Straight swap over in terms of calliper bolting on. The calliper end of the brake line is different though so you need to swap those over to... Ke30 is like this =>, ke55 is like this =<.
Yes vn rear pads fit ke55 calipers, give you some better pad options ie Bendix and ebc stuff.