Diesel Mufflers Quiet or LOUD?

A few things you have wrong with your plans. Number one you can not use a three inch exhaust pipe on an exhaust manifold made for two and a quarter inch tube. You must use two and a quarter inch tubing. Second you will never get a thirty inch long muffler under your car in the stock location . I've been doing this since 1977 I know what I'm saying. If you want to get a nice tone and better performance have your local muffler guy build you a two and a quarter "X" pipe and use Magna Flow mufflers and two and a quarter inch tail pipes. The sound is deep and mellow and it wouldn't drive you crazy. Take care Bryan