I’m going for a kind of stealthy look with my 68 XR7. You know - quiet exhaust, reasonably sized wheels, no stripes - but a lot of mechanical goodies tucked away underneath. I have been thinking that 17" steel wheels from a late model Crown Vic or Marquis might provide the right look if I paint them body colour and use a poverty hub cap. Maybe a decent performance tire around 225-50R17 would fit in the wheel wells and not rub. I might even have a set of custom white walls made by Diamondback Classics for an ultimately stealth look. Before I hit the auto bone yard, does anyone know if this will work? Thanks! 
Should work, along as they are not the really-late model ones with the negative offset.
I have 16" alloy wheels from a 95 Crown Vic/Grand Marquis on my Cat and they fit quite well.
Thanks for the reply! Seems like good 16" rubber is starting to get scarce which is why I was thinking of 17" wheels. No problems with hub size?
Hubs fit perfectly. I have Granada rotors but the “too-big” part has been machined down.
I haven’t noticed 16" rubber getting scarce, but I HAVE noticed that the price on 15" &16" rubber is getting quite high. What happened to the laws of supply and demand?
I think what you are describing illustrates the law of supply and demand perfectly!