ARP Custom Age 625+ Head Studs – Ford BA-FG

What is the difference between ARP2000 and Custom Age 625+ studs?

ARP2000 is an alloy steel that has a tensile strength of 220,000 PSI. Custom Age is an austenitic alloy that has a tensile strength of 260-280,000 PSI, providing a greater clamping force than that of ARP 2000.