Choose your manifold from the drop-down menu above and to the right.

M59-12 - 1994-98.5 DODGE  12V, 3 Piece Exhaust Manifold (high temp ceramic coated, assembled)

M59-24 - 98.5-02 DODGE 24V, 3 Piece Exhaust Manifold (high temp ceramic coated, assembled)

M59-24-3 - 03-07 DODGE 24V 2 Piece Exhaust Manifold (high temp ceramic coated, assembled)

Check the manifold on your Cummins regularly if you have made any modifications to your truck. The one-piece manifold has the tendency to crack under the higher EGT's they get exposed to in a high horsepower truck. The stock manifold is limited in how much exhaust it can flow as well. Your turbo depends on the air from the exhaust manifold to spin it up to create boost. If you flow the exhaust more efficiently into your turbo, you get faster spool up and better performance.  ATS manufactures their products in-house.  They are Made in the U.S.A.

Here's what ATS has to say about their manifolds: 

ATS Multi-Piece Pulse Manifolds for the Dodge Cummins application have pulse exhaust flow design, helping to spool up the turbocharger sooner with less exhaust backpressure and increase fuel efficiency.  This pulse manifold design eliminates the problems with shrinking and breaking, as well as cracking and gasket issues.  All Manifolds come Pre-Assembled with High Temperature Coating and Pre-Tapped for Pyrometer Probe.

ATS Exhaust Manifolds are available for the new Common Rail Cummins as well as both the 12 and 24 Valve Cummins. When looking for a performance exhaust manifold go with the leader, ATS is the original manufacturer holding the patent on the ball flange construction, stay away from other cheap copies being produced in China.