I have a 85 FJ60 that has 2 large holes in the muffler and the exit pipe from the muffler is pretty banged up. I want to cut out the Cat and replace the pipe from the collector on the manifold back with 2.5" pipe and either a 40 series or 50 series Flowmaster. I have never had this job done and want to know what a reasonable quote would be for it as I am shopping some muffler shops. Also is 2.5 too big for a stock desmogged 2F?