Exhaust Manifolds
A diesel exhaust manifold has to deal with heat, weight, and repeated expansion cycles. Cracked manifolds, shrinking factory pieces, broken bolts, and warped sealing surfaces are common on Cummins trucks that tow or run hotter than stock.
Cummins exhaust manifolds, 5.9 and 6.7 manifold upgrades, 12 Valve manifolds, gaskets, and hot-side hardware all fall into this category. A better manifold can improve sealing and turbo response, especially on trucks that tow heavy or run higher exhaust temperatures than stock.