Thanks for the feedback, 72c20customcamper and chevmn.
I was able to get up under bigyella today and learned a bit more.
Initially thinking the same as you 72c20customcamper, that I didn't have enough clearance between the pinion and the flywheel, I purchased, and added a couple size-variation shims, to no avail! I came to realize that I have the opposite problem...too much space. I removed the shim, and went back to a shimless install, then captured this video.
https://youtu.be/h0sBq31tRaA
I don't have the ability to machine the starter to get into the proper clearance of 0.020-0.025 as specified by Jegs. (what did you use to do this Mark?) I think I'm out of options with this particular starter, unless someone has a brilliant alternate idea.