DHD 300-120 DURAMAX HIGH FLOW MANIFOLD & UP PIPE BUNDLE 2001-2004 LB7

DHD High Flow Manifold Bundle

The DHD High Flow Manifold Bundle increases exhaust airflow by over 55% with no port modifications required. Even more gains can be achieved through port matching and blending.

DHD manifolds are cast from high silica iron — the proven standard in the high-flow manifold market. This bundle includes DHD’s heavy duty .120" wall 304 stainless steel up-pipes, featuring sleeved bellows and double welded pipe-to-flange connections for maximum durability.

The swept-back tapered inner port design helps accelerate exhaust gases toward the turbine, helping reduce EGTs and improving turbo spool.

Features / Benefits

• Reduced backpressure

• Improved fuel economy

• Lower EGTs and drive pressure

• Faster turbo spool

• 1/8" NPT bungs in each manifold for EGT or drive pressure sensors

Bundle Includes

• Right and left cast manifolds

• Right and left .120" wall stainless up pipes

• (16) 4340 chromoly M10 12pt manifold bolts (not cheap socket cap screws)

• (2) 1/8" NPT port plugs

• MLS stainless up-pipe gasket set (4 gaskets)

• MLS stainless manifold gasket set (2 gaskets)

• (12) 12.9 grade M10 12pt up-pipe bolts

Optional Upgrade: DHD In-House Porting Service

Want to get the most out of your investment? Add the DHD in-house porting service, which ports the manifolds to PPE oversize gaskets and gasket-matches the up-pipe connection. This is one of the most cost-effective ways to increase flow and help reduce EGTs.

Select the porting option above to add it to your order.
Note: This option adds 1–3 business days to processing time.

Notes

• The passenger side up-pipe is D-shaped to allow use with most aftermarket downpipes. Minor adjustments may be required depending on downpipe brand.

• There is no EGR riser on the passenger side up-pipe. This kit is not a direct replacement for EGR-equipped trucks and should only be installed on pre-emissions trucks.

⚠️ Important Legal Notice

NOT LEGAL FOR SALE OR USE IN CALIFORNIA. The manufacture, sale, offer for sale, or installation of this product may also be illegal nationwide under the Federal Clean Air Act (42 U.S.C. § 7522(a)(3)).

This product is for closed-course racing use only, where permitted by law. Any other use may violate local, state, and federal laws. DHD or Delaney's Diesel is not responsible for unlawful use of this product.