Hello
I have a different setup than most on my 250, I run a early 60s 292 manifold with 2 1/2" outlet (no heat riser) the 2 1/2" pipe is 36" long then jumps tp 3" goes to a stock late model 454 3" in 3" out then runs a single 3" pipe out the back. Sounds good when on highway but talks to you when you romp on it. Information only one 3"pipe flows exactly the same air as two 2" pipes. The stock 454 muffler is not quiet because it doesn't have a convertor in front of it. It is designed to let a 454 get good mileage plus pull large trailers which means that a 254" six would have to turn about 9000 RPM to hit the design flow of the muffler.
Big Bill
