Engine bolt torque specs are usually specific to a particular engine. Automotive products manufacturer ARP, however, provides brand-specific torque specs for each of its fasteners. ARP main stud kits come with nuts and washers, in addition to the studs. ARP main studs feature a 200,000 psi tensile strength.
The engine block threads and the studs should be cleaned before installation, and it's important that you use a properly calibrated torque wrench. Lubricate all threads, nuts and washers with ARP's Ultra-Torque fastener lubricant before installation. For permanent stud installation, use a cement adhesive such as Loc-Tite. ARP provides a standard set of torque specifications for its fasteners based on size but advises users to verify listed torque values against the instructions provided with each main stud kit.
Use ARP main stud kit 135-5402 for two-bolt mains in 396, 402, 427 and 454 CID engines. Use kit 135-5601 for four-bolt mains in 396, 402, 427 and 454 CID engines. For two-bolt mains in 396, 402, 427 and 454 CID engines with a windage tray, use ARP main stud kit 235-5502. For four-bolt mains in 396, 402, 427 and 454 CID engines with a windage tray, use kit 235-5701.
For Mark IV aluminum block engines, use ARP main stud kit 135-5603. Use kit 235-5702 for Mark IV bowtie engines with a windage tray; kit 135-5606 for Mark V and VI 502 engines; kit 235-5606 for Mark V and VI 502 engines with a windage tray; and kit 235-5602 for Mark V and VI bowtie blocks with splayed cap outer studs.
Use ARP main stud kit 235-5601 for Dart Big M engines with splayed cap bolts and kit 235-5603 for Dart Big M engines with splayed cap outer studs.
For World Merlin II and III blocks with outer bolts, use ARP main stud kit 135-5801. For World Merlin X aluminum blocks with outer bolts, use kit 135-5607.
Torque all 1/4-inch main stud nuts to 14 foot-pounds.
Torque all 5/16-inch main stud nuts to 28 foot-pounds.
Torque 3/8-inch main stud nuts to 50 foot-pounds.
Torque 7/16-inch main stud nuts to 80 foot-pounds.
Torque 1/2-inch main stud nuts to 125 foot-pounds.
Torque 9/16-inch main stud nuts to 180 foot-pounds.
Torque 5/8-inch main stud nuts to 240 foot-pounds.
