New life for an old 340 (stock stroke)

Yep. From your numbers your block was .046 OVER the max deck height of the block.

I was told that Chrysler would only take enough off the casting to get a clean, flat surface. That's why some ran like dogs, and some ran like a striped *** ape. When you have a tall deck, a set of rods at the blue print minimum and maybe a set of Pistons that were short on CH and you'd get one with 9.25:1 instead of 10.5:1 with all the tolerance stack up.