The problem is that it's too late to be trying to address torque vs. stretch, or even stretch or torque values.
You need to tighten the bolts to the same point the machine shop did when they re-sized the rods. And THEN you need to hope that the machine shop torqued them the proper amount! Since the machine shop most likely installed the bolts, they--hopefully--paid attention to the instruction sheet that was packaged with them.
Is there any way to contact the machine shop that did the work?
The last-ditch method would be to take your best guess at torque values, and then measure the bearing bore to assure it's round.
By the way, rod bolt stretch gauges are now being imported from Communist China--which means you need to verify the accuracy and repeatability of the tool you contemplate buying. (all the ones I've seen come with the dial indicator) What good is a stretch gauge using a dial indicator that only reads to the thousanth, and has a crappy weak spring?