This ARP 135-3602 BBC High Performance cylinder head bolt kit is for Chevrolet Big Block 348-409 with Cast Iron OEM heads. The reduced wrenching hex head eliminates the need for valve train removal to facilitate cylinder head retorquing. All High Performance Series bolts are 180,000 psi (which is 15% stronger than Grade 8)! Kits come complete with hardened parallel-ground washers. Sold as a set of 32. ARP 135-3602 BBC Head Bolt Kit Fits: Chevrolet Big Block 348-409 with Cast Iron OEM heads Which is better, either cylinder head studs or bolts? The answer depends on the installation. On many street-driven vehicles, master cylinders and other items protrude into the engine compartment. It’s probably necessary to use head bolts so that the cylinder heads can be removed with the engine in the car. The ARP 135-3602 BBC Head Bolt Kit is perfect for that application! Studs also provide more accurate and consistent torque loading. Using studs ensures easier engine assembly, and proper alignment of both the cylinder head and gasket. Here’s why: when you use bolts to secure the head, the fastener is actually being “twisted” while it’s being torqued to the proper reading. Accordingly, the bolt is reacting to two different forces simultaneously. Install a stud in a “relaxed” mode – never crank it in tightly using a jammed nut. Always install the stud hand tight! Then, when applying torque to the nut, the stud will stretch only on the vertical axis.
