I had the engine all together and then thought about everything I had seen for rod clearances on the bbc rod clearances.
The clearances were sitting in the .002 range, one at maybe .0019 and 2 at .0029. I went through the gm manuals I have and they have .0015-.0025 clearance listed while the bearing rule of thumb makes for a clearance of .0022 with clevite saying to add .0005 to that for performance use. So I took it all apart and started over with more bearings.
It took 2 full sets + 2 spares of rod bearings to get to it, but I got all 8 rods to .0024-.0026.
For anyone else ever doing this, yes swapping out the lower shell from std to -.001 does give .0004 to .0006 more clearance. Even swapping between bearings of the same part number from box to box will give some variance. I found some big std size bearings and some small std size bearings.
Its an eagle 4.250 crank and rods, all new, the crank pins had about .001 variance between all of them. Rod big ends all measured the same.
Now I have to decide if I should roll the dice with a rubber rear main seal on a crank with knurling, can't find a rope seal locally anywhere.

You are not being too fussy. A friend and fellow mechanic that I worked with nearly 30yrs had a saying,"there's always enough time to do it right the second time".Truer words were never spoken.I' ve just finished finalizing all clearancing except for 1, 2nd groove compression ring. It's on the way, thanks to a Summit employee willing to go the extra mile with the manufacturer, superceded part numbers, and getting it entered into the Summit system so it it can actually be ordered and shipped. I found just how much easier and quicker cast second rings file than the Hellfire nitrous top rings do. Lesson learned. Clearance right, sleep at night! Bill

Were all your rings on the tight side in the pistons? I used icon 842's that came with the total seal ring package. Min spec is .0015 groove clearance, all the rings were a tight .0015 at 70 deg f.

I used a set of Diamond pistons and clearance was good, I just messed up and went too fast filing that 1st in line cast ring .My fault. Bill

So true, there's a similar saying in the fabrication world, "there's never enough time to do it right, but there's always enough time to do it again."

Were you using Clevite CB-743-HN and mixing with CB-743HXN?
How many rods needed one of each to get your desired clearance?
Did any use both halves of the HXN (extra clearance bearings)?

I mixed hn tops with hxn bottom on 6 rods, then mixed and matched hn's on the last 2. Using all hxn's resulted in .003+.
There are some areticles out there that say you can move uppers to lowers and it doesnt matter, but I kept all uppers in the connecting rod and all lowers in the caps.

I mix STD and X bearings on most all my small blocks to get .0025 - .003 but for big blocks I typically use the full set of X bearings to get closer to .003 to .0035

I much rather have .0025+ rod bearing clearances than .0021 or less