ARP Intake Manifold Bolt Kit, Hex Head S/S (AR430-2001)INTAKE MANIFOLD BOLTS, GM LS fits GM LS1, LS4, LS6, 4. 8L RL4, 5. 3L LM7, 6. 0L LQ4 Part Number: AR430 2001 Prevent Intake Manifold Leaks With Arp's Quality Fateners. They Are Rated At 170,000 Psi And Precision Machined For Optimum Thread Engagement. Wide Underhead Flange And Companion Washes Provide Even Load Distribution. Precision Rolled Threads Prevent Galling While Promoting More Consistent Torque Loading. Facilitates Optimum Sealing Of Gasket