I have dabbled with a stretch gauge in the past with not so good results. The gauge would never repeat each time it was removed and my numbers where all over the place...
I feel your pain as that was pretty much my experience as I attempted to do this for the very first time. After a few tries I discovered that the gauge tension needed to be much higher to make it less susceptible to even the tiniest movement. Replacing the dial indicator spring helped greatly. Still, I would have a steady reading that all of a sudden would jump by like 0.005" or so...ugh???
Well, the 2nd part was to make sure that the rod bolt ends and my gauge and dial indicator locating pin/foot left no room for the bolt to move around. Off shopping I went, picked up a set of these attachments with different shapes and found one that would mate very well.
These two steps were key to getting repeatable results.
Having said that...my Eagle H-beam rods had the Eagle ARP S2000 bolts, spec'ed for 0.0064-8" stretch at 75 ft-lbs. I went through 3 ON/OFF cycles, in the proper connecting rod vise, using the ARP lube, eventually got them to 85 ft-lbs and stopped there. The numbers were repeatable but I could not get them to that 0.0064-8 stretch.
