Boost Tube Upgrade Kit Fits 20-26 Chevy/GMC 2500/3500 6.6L Duramax, L5P Red Powdercoat Banks PowerBanks massive 3. 5 inch boost tubes are the largest on the market, flowing 26 45 percent 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. Every other competitive product on the market tops out at just 3. 0 inches, and your factory