I got a magnaflow on my Vortec 4300 in my Blazer man that gave it some sound. Im leaning towards either Glass packs of Magnaflow when my truck gets done. Probably glass packs first cuz their cheaper. Itll be a 400 that has been played with some. I havnt heard a SBC with magnaflow yet and I dont really wanna dump all that money into two mufflers for true dual and then decide i dont like em