This kit, part number AFA-3406ESK, includes the proper quantity of each stud and nut for these engines, the company says
AFA’s exhaust studs, part numbers 1061792 and 1061793, and nuts, part number 2N2766, (all available separately) are manufactured in state-of-the-art OEM manufacturing plants, using the highest grade of steel so that there is no chance of head bolt failure when torqued to the proper specification, AFA says. Studs and nuts should be replaced together as instructed by the OE Service information.
The company says replacing the studs and nuts on the engine insures that the exhaust manifold
will be sealed tightly without leakage and that the combination of AFA’s stud and nut kit and exclusive exhaust gasket components offer the best sealing available for the Caterpillar 3406E/C15 engines.