Super Stock Headers

Good question, I would say it was in that ballpark. I know my carb mounting pads were level at the time of mock up.
---
I'll be installing my hemi in the fall, I'll check it and share. I'd guess that it's going to be about 2 degrees.

For the Dart though I built my engine plate mounts with the block exactly as your measurements indicate. I'm sure the TTI's will fit like a glove.