stacks
Unless you plan to increase the size of your turbo outlet it is much easier to stay with 4" or 5' as this is stock for larger trucks. You should be able to find deals on this stuff at any truck jobber and save some beans including chrome and band couplers. Stemco and Donaldson are both manufacturers including mufflers, the CTD boys on this site can direct you to a quality but free flow muffler. Running stacks brings the noise closer to the cab but gets fumes up off the ground depending on length above cab. The locals are starting to get fed up with open CTD exhaust systems here and if they see straight pipe your buying. Always costs more to replace to stock than to find reasonable free flow muffled solutions.