My exhaust is corsa. They exhaust above the water line on the side. No "S" in my exhaust. But when the corsa is closed it is run through the drive. Is there much of a chance of reversion? Is it safe to remove the turbulators in this application. Its a HO. There are spacer between my manifolds and risers. They are about 4"-6". Does anyone know of any tall headers? Or are new manifolds my only option? Always looking for some more ponies as my boat is a heavy pig!