So as not to have a thread a mile long, here is my new thought. Today I purchased new grade 8 bolts, two per caliper, and castle nuts for each plus 1/8 inch cotter pins. I will drill the bolts 1/8 inch through, torque the nuts on full as I can after lubing with Lock-tight. AAJ either provided 1 3/4 inch grade 8 bolts or said they were required, and the nylon locknuts should have been sufficient provided the nuts were torqued sufficiently. In my son's case, insufficient torque or some-other reason caused trouble. There is room to use longer grade 8s and use two nuts and a lockwasher between them as a fail-proof scheme.
Larry Jett: I live in my own little world; but that is OK as everybody knows me there!!