Random numbers are the common result! I'll sonic check Chevy blocks and they are nice and consistent from hole to hole then switch over to a Mopar block and one hole will be .243 thrust and the next hole will be .147 on the thrust.

They are just all over the map. Core shift is very common as are random thin spots. I'd say that over the past 20 years roughly 50% of the Mopar blocks I sonic check are too thin to build into race engines.

I'm building a low deck 470 right now and I passed on three blocks before I found one that was good enough to use.