If you decide to go with a packed straight-through design then go with the Dynomax Ultra-Flo instead of the Magnaflow for the simple fact they tend to be much less. I run two 3" Ultra-Flos on my B block and only paid $80 each for them (the fully welded non S/S type). I love the Magnaflow too, don't get me wrong, but the Dynomax's are cheaper.