Rusty, When the guy's got back from the bolt store(yes, we have a place that sells nothing but nuts and bolts), I put the bolts in dry, then turned the motor by hand. No problem. I then removed them, saw that there was about half an inch of threads making contact, dropped on some red loctite and reinstalled them. Later, they told me, "oh, by the way, they didn't have 55mm, just 50mm"
The best part of this story is, we installed the motor this afternoon. It cranked three revs, fired and ran.
I wish I had the means to run the motors on the bench first.