18" wheels

rich_mc said
This one: Wilwood Disc Brakes - 1976 Plymouth Scamp All - Front Brake Kit No.: 140-15468-DR

It appears to not alter track width, but I don't see any info about the hub diameter.

The hub dimensions are right on that page. That’s the one I was talking about, the hub diameter is 3.1”. Which is gigantic, even the factory hubs limit wheel selection some and they’re only 2.7”.