I know that this forum is here to help others, so I thought I'd give it a shot and post a topic on rod bolt installation - rod bolt stretch when using ARP or Raceware bolts. Sometimes we have bottom ends that have already been built but without the good rod bolts. Yes, you can measure stretch with the rods in the case on the cheap. Many here have suggested that this is not possible, and rightly so with a regular micrometer or a stretch gauge. What you need is a good "donor" micrometer, one that you can do without. Cut the ends off even and then taper the flat faces to a cone, leaving just a small point of hardened surface area on the original tips for the rod bolt centers. Then weld the ends to a long bolt. You need to jig the cut ends of the decapitated micrometer as strait as possible on the long bolt before welding. I used a large bench vice. Take the tiny set screws out of the vertical shaft of the micrometer so that you can "zero" in each bolt by turning the shaft. Tighten the rod bolt to torque and then measure again. Easily fits inside the spigots onto the bolt center holes. You have to zero the base of the micrometer to a horizontal range point for each bolt before any torque is applied because each bolt is of a different size. Works great, very precise. I tested this home-made-in-twenty-minute contraption on an ARP rod bolt at the machine shop against their expensive stretch gauge and got equal readings.
