Originally Posted By Jim_Lusk
In my experience, Flowmasters have a drone sound only with headers. With cast iron manifolds they don't.



The Flowmaster drone was so bad I added some Magnaflow resonators out back. Sound at idle was retained, drone while driving was reduced.
This was with a 2.5" H-pipe TTI exhaust, HP manifolds, and 3:55 gears.
I have Dynamax's is another car, MUCH happier with them.