Buying '93 GT - what do I need to look for?

Howdy - In 1993, I bought a GT right off the showroom floor. In an effort to relive my youth (and have some fun with my son), I am looking at a '93 GT for sale in my area. Since I sold my original GT with 26,000 miles on it (not a convertible), I'm not sure what goes wrong with these with age. It's got (gulp), 99,000 mils, but appears to have been well maintained. What do I need to have a mechanic inspect closely? What should I expect to need to repair or ask if it's already been taken care of? I've read some about heater cores - is there a way I can check that? I realize it's almost a twenty year old car and it's gonna need some things - I just want to know what I'm getting into. Your feedback is much appreciated!