Dual Exhaust System Recommendations ?

Hi,

My '68 Dart currently has a POS dual exhaust system on it that I managed to "clearance" on a speed bump the other day (the car is lowered slightly). Currently, the car has a stock 318, but a mild 383 is in the works. What systems are out there that fit well, up tight to the chassis that I can use for my 318 and eventually the 383 when it goes in...??

Thanks,

Mark.