Mustang Newbie Here

I've been looking for a project and recently I purchased (rescued) a 1987 GT Convertible from a high school kid. This is truly a project. Only 77,000 miles and runs great. I also found a 91 LX convertible (cheap) that I can use as a donor car for parts. Question is, Are there any parts that won't interchange with my 87? Specifically, radiator, interior, fender.....