Grand Rock designs these stacks to work with their crossover pipe. Bigger exhaust means more mass air flow and lower exhaust gas temperatures. A 36" stack will get to the top of the cab.

Grand Rock has been doing big rig stacks for 30+ years. They bring that same superior craftsmanship to the stacks for diesel pickups. The bigger the exhaust the more mass air that flows. This helps to lower the exhaust gas temperature known as EGT's. This is very important when you have chip'ed the truck and are producing more horse power then stock. Grand Rock PowerFlow, get stacked for power.