If you've increased air flow with a a larger S400 turbo the next step is fuel upgrades.  Increase fuel flow with BD Diesel's Venom Dual Fueler.  It's the perfect fuel upgrade to maximize the power of a larger S400 turbo..... 

BD Power Super B Twin Turbo Upgrade Kit for Super B Single - 1998-2002 24-valve Cummins

LBZ Duramax Injector Nozzle, 2006---2007 Race6 40 Lpm 100%

• Direct fit for the 6.7L Powerstroke
• Mandrel-bent, polished aluminum pipe eliminates restrictive bends
• Improves airflow, power, and EGTs
• CNC-machined factory-style coupling allows for quick install
• Includes Mishimoto Silicone Boots with DuraCore™ Technology and Mishimoto Constant-Tension T-bolt Clamps
• Installs in under one hour
• Mishimoto Lifetime Warranty

Turbo Guard Kit - Steel Adapter / Silver Valve

Built-It Trans Kit Ford 2003-2004 5R110 Stage 4 Master Rebuild Kit 

Features:

• Fits 2011-2016 F250/ F350 4WD
• Level Lift Coil Spacer
• Max Lift 2.5 in. Incl. Front Coil Spacers
• Track Bar Drop
• Front Shock Relocation Brackets

S&B 2003-2007 Dodge 5.9L Cummins Cold Air Intake Kit (Cleanable Filter) 

Fits all 2008 - 2010 6.4L Ford Power Stroke

Replaces the factory turbocharger, exhaust manifolds, intake piping, and charged air piping with H&S Motorsports quality parts. (Divided T4 Pedestal)