Yes, they will fit. Make sure you get the metal brackets that the plastic pieces mount to as well. There is one on the front fender, one on the door, and one on the rear quarter behind the door.
Les' car is now sporting a rear bumper cover from an '89 SC, in addition to the SC side skirts the car has had for years now. I don't know if he's got any new pics showing this yet.
That black XR7 looks great! The rear bumper is wasted on mine anyway so definitely going with the SC rear cover.
I bought a black front cover to replace the wasted one on my white SC. Thought for a second of putting it on the cat but after looking closer looks like no go. Way too different.