I have 9x15 revolutions with 225 tyres on the back of my Capri with standard arches, they're got quite a deep dish and I needed a mk1 3l axle for them to fit. There's plenty of room though so with the right offset 9" would fit on a standard axle.
Escort cossie wheels are 8x16, I've seen a couple of capri's with them and I'm 99.9% sure they more than fill out the standard arches without spacers, they do have quite a dish on them.