DHD 300-121 Duramax Tubular RACE Manifold & Up Pipe Bundle 2001-2004 LB7

DHD's new thick wall tubular manifold bundle increases exhaust air flow over 45% without any port modifications. An additional 30% in flow gains can be found in port matching and port blending. These race manifolds are constructed of thick wall .130" stainless tubing, 1/2" thick steel flanges and tig welded inside and out. Included in the race bundle are our .120" wall thickness 304 stainless steel up pipes, featuring sleeved bellows and double welded pipe/flange connections.

Going tubular will save weight and improve fitment around engine mounts, control arm mounts and aftermarket cold side pipes.

We have over a year into testing these manifolds on multiple competition vehicles, including our ProStreet truck Last Minute Hooker. We are confident in their ability to flow and withstand extreme EGT's. You wont find a lighter, higher flowing, more versatile Duramax manifold. 

Features / Benefits:

• Reduced Back pressure
• Tubular Construction Allows Direct Mount Wastegates
• Save 5lbs Per Manifold vs Cast (9lbs vs 14lbs)
• Increased Chassis Clearance
• Improve Fuel Economy
• Lower EGT's and drive pressure
• Quicker turbo spool up
• 1/8NPT Bungs in each manifold for EGT or Drive Pressure Sensor
• Manifolds Accepts DHD 300-122 Thermal Blankets

Bundle Includes:

• (RAW) Uncoated Right and Left Fabricated .130" Stainless Tube Manifolds
• Right and Left .120" Wall Stainless Up Pipes
• 16 4340 Chromoly M10 12pt Manifold Bolts (Not cheap socket cap screws)
• 2x 1/8NPT Port Plugs
• MLS Stainless Up Pipe Gasket Set (4 gaskets)
• MLS Stainless Manifold Gasket set (2 gaskets)
• 12 12.9 M10 12pt Up Pipe Bolts

Notes:

• The passenger side up pipe is D shaped to allow for use with most aftermarket downpipes. However, slight modifications may need to be made to get the best fit depending on downpipe brand.
• There is no EGR riser on the passenger side up-pipe. This kit is not a direct replacement for trucks equipped with EGR and should only be installed on pre-emission equipped trucks or vehicle not licensed for street use.