Thinking about picking up a Flowmaster 40 series for the Firebird (don't need a new muffler just yet, but a buddy is selling it quite cheaply), but I have the 3.1L engine. I know the 40 series is a loud muffler, and that doesn't bother me, but I'm concerned about putting it on a 3.1L car. Will it end up sounding little better than open exhaust, or will it have a half-way decent flowmaster sound? The exhaust currently is all stock.