stock one provides too much backpressure and restricts smooth flow. a good system will have backpressure, but not a lot of restriction (like the packing crap thats in your factory muffler). single 3" is good for most of the trucks on this board, duals are a waste of money IMO unless you have some serious money into your engine.Stoked said:well if you are trying to create more backpressure, just slap the stock muffler back on it! thats backpressure right? i dunno about this whole backpressure creating more power issue, if that is sooo true than why do people change there exhaust atall?