Just need a set of hub adapters, just like a spacer really.
Whether they'll stick out past the arches or not I couldn't say.
But if they do and you fit a big arch kit I'd say it's going to look rather silly.
isn't 20" rims on a tratter a bit like a peep hole bra on an octogenarian. Just a bit wrong, you'll be gassing the suspension and fitting a massive stereo next:5bconehead: