Banks Power 19-21 Ram 2500/3500 6.7L Cummins Boost Tube Upgrade Kit - RedBanks massive 3. 5" boost tubes are the largest on the market, flowing more air than stock! Smooth mandrel bent tubes deliver more air to your engine while reducing boost pressure loss resulting in quicker turbo spool and more power. Banks Boost Tubes are the largest charge air cooler pipes in the industry, measuring in at a full 3. 5 inches. The factory intercooler pipes are 2. 70 inches in diameter on the hot side with crush bent corners and 3. 15