3.Next, the rod bolts are torqued just shy of the recommended torque spec. In our case, ARP recommended the bolts be torqued to 70-75 lb-ft or stretched to .0050-.0055 inch. Most of the bolts did stretch to .0050 inch with 70 lb-ft of torque, but several required up to 80 lb-ft of torque in order to stretch properly. There are two reasons for this: The torque method is sometimes inaccurate due to varying coefficient of friction at the interface between the rod and the bolt. The other reason could simply be an inaccurate torque wrench. This is where the stretch gauge becomes an invaluable tool. Without the gauge, we wouldn't have known that the proper preload on those specific bolts was not achieved by torquing them to the minimum value.