Check out ARP's engine assembly tools, including the rod bolt stretch gauge, which is the Tool Of The Month for June 2009. Automotive Racing Products' rod bolt stretch gauge makes measuring the ...

All ARP connecting rod bolts have a small dimple placed on both ends of the bolt that accurately position the rod bolt gauge pins on the bolt. Next, zero the gauge on the relaxed bolt.

This is a dangerous condition, because stretch is directly proportional to clamping load between the rod cap and the connecting rod. The ARP stretch figure is 75 percent of the bolt's yield strength.