360 block

70aarcuda...are you saying there is nothing else special about these blocks when comparing to other model year 360 blocks

If he's not I certainly am. The possibility is good that a pre-magnum roller 360 block will test thin. But my experience has been they usually are better than any of the earlier year pre-magnums because the earlier ones are badly core shifted. It is rare that ANY mopar factory block is free of core shift. Even the idolized early 70s production ones. That's why I test all of them I do.