If you have access to a micrometer, you need to measure the crankshaft to make sure the rod journals are round, and the same diameter from front to back. This requires an accurate micrometer, and someone who is skilled at using it. No, a dial caliper isn't accurate enough. .0005" (1/2 thousandth) is a strand of hair split into 4 equal slices. The maximum "out of round" needs to be less than .001". and "taper" from front to back needs to be less than .0005". If you start disassembling rods, be aware that the shims between the rod and cap are VERY thin and fragile, and unless you're adjusting bearing clearance they need to go back in exactly the same place they came from. The rod caps can also be reversed, so carefully observe any markings on them BEFORE disassembly. It sounds like someone might have already done some mixing and matching, especially if the rod numbers don't match the cylinder numbering- - - -1 through 6, from front to back. Following up behind "Mr. Bad Wrench" and correcting his mistakes was always one of my least favorite jobs!
Your machinist is going to want to do his own measuring, but be absolutely sure he is experienced at checking and adjusting Babbited rods- - - -if he's less than 60 years old, it's pretty unlikely!
Jerry
