Yeah, If the pads overhang the rotors by ~.25" then is uses the large rotors, "XR2 size" I have a set laying around somewhere
I've seen it done before, it caused severe stress on the rotor inducing cracking, and since a large portion of the pad does not wear at some point the two pads will contact and BAM no more brakes...really dangerous.
Also, I can't imagine braking would be all that great because the swept area is reduced dramatically