225 exhaust advice needed

If you also got the Super 6 exhaust manifold, you have an outlet diameter that will work with a 2.25" pipe.

My Demon 318 with a warm up has duals and my stock /6 73 has a single 2.25" pipe. The 73 uses a generic "turbo" muffler and a PowerPipe SC exhaust manifold. The tone is a little deeper, but still sounds like a /6.