I am positive that the rear main was installed correctly - this motor has 14,000 miles on it and the rear main looked perfect when I took it apart - #5 rod journal is the only bearing that had any damage - rod journal #6 also has a small crack but the bearing still looks good.
The thrust bearing did have some uneven wear - likely from the crank flexing under load.
This crank came from a pile of parts I picked up from an guy who saved them from getting scrapped after another GMC nut had to abandon them for lack of any place to keep them as he got older.
Here is one of two loads that I hauled from his barn. You can see the pile of cranks in the middle of the load - there were 4 6-bolt cranks and 4 4-bolt cranks and a dozen heads including small and large port heads with several H-Heads in the mix.
So I don't know the history of the crank. I dropped two more 302 cranks off today at the machine shop that grinds a lot of cranks in the Portland area - they will clean them up and check for cracks and pick the best one to grind. I only have bearings for 0.030 under for rods and mains now (Moraine 400's NOS) - so I hope the one that is M0.020 /R0.020 is good and we will go with that one.
