AIR RAM PERFORMANCE is the FIRST to the market with ARP HEAD STUD BOLT KIT for the Dodge/Jeep 4.7L engine. These kits will allow you to run up to 25lbs of boost. THESE ARE IN STOCK AND READY TO SHIP!
ARP 8740 HIGH PERFORMANCE SERIES
This ARP head stud kit is made from 8740 chromemoly steel, 190,000 psi tensile strength. It is precision centerless ground and thread rolled to Mil-S-8879 specs. Each kit contains 20 studs, hardened washers, and 12 point nuts.
ARP 2000 PRO SERIES HEAD STUDS
Manufactured from ARP 2000 grade (rod bolt) material,
these studs are designed to bottom on existing block bolt
threads resulting in increased engagement and reduced
thread stress. At 120 ft/lbs of torque (using 30w oil)
these studs result in up to 35 Percent greater clamping force
and do not require re-torque. Each kit contains 20 studs,
hardened washers, and 12 point nuts.
Head Studs Vs Bolts, Technical Discussion
ARP's factory Tech Representatives are often asked which is better, cylinder head studs or bolts. The answer, invariably, depends on the installation. On many street-driven vehicles, where 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.
For most applications, however, studs are recommended. And for good reason. Using studs will make it much easier to assemble an engine (especially a racing power plant which must be serviced frequently and quickly!) with the cylinder head and gasket assured of proper alignment. Studs also provide more accurate and consistent torque loading. 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. A stud should be installed in a "relaxed" mode - never crank it in tightly using a jammed nut. If everything is right, the stud should be installed finger tight. Then, when applying torque to the nut, the stud will stretch only on the vertical axis. Remember, an undercut shorter stud will have a rate similar to a longer, standard shank stud.
This provides a more even clamping force on the head. Because the head gasket will compress upon initial torquing, make sure studs and bolts are re-torqued after the engine has been run.
