My problem was that the longer standoffs would not let the nuts spin on easily and I was afraid of stripping the thread. I decided what the heck, and used the longer standoffs and carefully threaded the nuts on and then used the little tool to tighten these in a crossing fashion. Somehow the instructions should give some sort of designation like 140mm and 100mm standoffs and which is to be used where. I a mechanical engineer and these were not the best instructions to follow.
System is up and running.