New floor pans for those you have look like Swiss cheese, and you'll just be constantly repairing and patching one area after another as they rust out, and you'll end up with a Fred Flintstone mobile, so my advice is get new floor pans and install them and be done with it, especially if you have put a lot of work and effort into truck, for they don't make trucks like the Dents anymore. Hopefully you'll find this helpful, in you decision .
tj one thing I always do on my trucks is to clean out and under coat the inside of the cab mount housing this is a bad area on these trucks that are always filled with mud/moisture. this =s rust in the floor also