340 .040 Bore Okay?

I've done several and like RB, I did find a pattern with the early 360 bocks. More consistent and thicker than the later blocks. Not every one, but most by a good margin. I tested probably 6 or 7, I don't remember. It's been several years ago. I just recently got a sonic tester myself and will be testing all of the blocks I have here. As mentioned above, I've already tested the slant 6 block for my next build and it is ridiculously thick. It is also the "BH" casting block, which is rumored to be thicker....but you know how rumors are.