They are pretty nice. I got the widest ones they had. They come with a wire stiffener that can be inserted into the outer lip to keep them in shape once installed. If trimming the fenders, you will need to build up a flange inside the fender opening, since they need to be screwed or riveted into the inner lip of the fender. Another thing to note is that they prefer to install into nice even curves. I had to open up some of the more squared off wheel well openings on my '85 to make them fit better. Here is the first fender trimming I did for the front:

Before shot, lower fender is trimmed but no lip:




Added lip insdie lower fender and smoothed out the front curve: