My 89 SC went 200,000 miles before I sold it. Fine car, handled nice and had good brakes....while the ABS lasted.
You will most likely have a far larger radiator so the coling issues will be gone, The ABS won't be needed. the rear end can be interesting. I'd look at making tubular contol links. I think I paid about 100 bucks each for the rear calipers. They are self adjusting and have a parking brake built in.
The motor made 14 pounds of boost most of its life and I had very little trouble with it. Plug wires once a year and platnum plugs were necessary.
Here is a link to the SC club of America. The best site for SC information. Everything that has ever happened to a SC has been covered here. Also a good source of parts.
http://www.sccoa.com/