After perusing the audio forums and reading about the various options available to me, I decided to go with Rockford Fosgate 6.5" components in the front and the rear on my 91 FC. Here's where the installation troubles begin. After taking out the door trim and attempting to insert the speaker in the front doors, I noticed that it hits the window and the metal frame behind the trim. In the back, I think I had un-amped 4" speakers and could not get my 6.5" to fit there either. I'm sorta stuck because I've read that 6.5"'s can fit without cutting but I don't see anyway they can fit. My ideas are to build a custom ring for the back speakers and to drill/dremel a space through my door trim to fit the 6.5"s in the front. Is there any other alternative that I can pursue without having to cut/custom build?

 

When I put a new sound system into my own car I had the same problem as yourself. The thing is that FC doors don't provide much depth for mounting. You probably won't be able to get past the problem with the window coming down and hitting the speakers. You can get the 6.5"s to fit in the back by making a ring, but it would ruin the whole point of buying the nice components since all the sound will be behind you. I would say just go for it and spend the money on a custom pod installation. You'll probably lose some leg space up front though.