Callies Performance Products in conjunction with ARP (Automotive Racing Products) has introduced the industries first series of serialized rod connecting rod bolts. With individual bolt serialization engine builders will now be able to record and accurately recall the free length and stretch dimensions of each fastener individually. Produced from Custom Age 625 material these bolts are available for all Callies Ultra SBC and LS type connecting rods. This permits builders to keep very accurate records about the each bolt's dimensional integrity and it
can be of significant aid in failure analysis. 

SOURCE
Callies Performance Products
419-435-2711  tech line
www.callies.com