ARP Cylinder Head Stud Kit 150-4069 ARP Cylinder Head Studs fits 83-87 Ford 6.9 Diesel Engines ONLY ARP cylinder head studs are cold-forged to ensure molecular integrity. They're heat-treated prior to thread rolling and machining. ARP Pro Series kits are also available with... MSRP: Was: Now: $299.65 Out of stock. Please Call For Availability