I want to replace from the turbo to the main converter. I will be replacing the stock main cat with a high flow replacement. Does anyone know if the RB part number "S16207" without the presilencer will work? It says it replaces the cat and then the presilencer mounts to the "y" pipe. Could it be that this presilencer is the stock length as the main cat?

I would be open to any suggestions for a down pipe that will fit my requirements of stock size cat and "y" pipe.

-billy