I could be wrong, but I think those look like the original MII rotors, or maybe Granada 10" rotors with GM calipers. What is the diameter and bolt pattern? Give one of the brake companies a call, there are several different 11" rotors available, some make the track width wider than others.
ECI has some brake kits and they say which ones move the wheels out from the stock location and which ones don't.
Be careful if you start trying to use parts store rotors, pretty much all of the swap rotors that come with the brake kits have mix and match bearings and races to get them to fit the MII spindle...Some are actually less than perfect matches too, but seem to work. (case in point: I once got a set of rotors for a fatman kit, and they sent out a rotor with a bearing race to install that actually lets the rollers hang out the race a little bit)