First, the shocks not leaking, is just rusty salty winters . the part # 10425, its like a glass pack with the hole straight through, but it doesn't at all sound like one. its very deep until you floor it, then it almost sounds ricey, almost. and cruising at 55, its low and you can tolerate the volume. if your looking for low volume, go with a stock muscle car muffler like the flowmaster 40 or 50 series, no need to change pipe sizes.