You can minimize or even eliminate rubbing by using the correct tire sizes, wheel offsets and shock absorbers. One common problem area is using a shock absorber that is too short. This can cause rubbing because the suspension compresses too far. It can also shorten the life of your rear-upper ball joints and even ruin the top tapered hole in the upright . If your shocks are any shorter than the ones recommended by Julian, earlier in this thread, you can solve the problem by adding an extra bump rubber per shock absorber. Bump rubbers don't last forever, so keep an eye on them.
If you have rubbing problems at the front, it might not be due to tire width. Rather, it could be due to tire height. If your tires are taller than 24.8", they are too tall. A 235/40-17 is much less likely to rub than a 225/45-17. Keep in mind, our much beloved 225/50-15 Pirelli P7's were only 23.9" tall! Naturally, I'm referring to what works on a narrow bodied Pantera.