340 block or 360 block

No neither bores are fresh, so a next size up over bore is going to be needed. I know we are splitting hairs between the two blocks. I was just wondering if there was a strength factor between the two. Especially since the 340 is a 69 block, which was told was a high nickel block.

As mentioned have the bores sonic checked, also have them measured for wear. They may not need to be bored.