This is the first system on the market with a true ''straight thru'' flow path. That means that even though there is one muffler there is two completely separate flow paths for each side of the exhaust. There is absolutely no loss of flow thru the muffler. All other systems include a flow path that create turbulence and restricted flow in the muffler. This header back system includes a driveshaft tunnel X crossover kit for maximum ground clearance even on lowered vehicles. Manifold downpipes are available as an option for those that do not have headers. Great for even the highest performance(up to 600hp) applications where ground clearance and OEM ''look'' is a priority.