You‘d be surprised. On a 460 Ford it was that far off. A cheap assed regrind.
And that ASSUMES the dot is in the correct location. You can’t assume that. I’d explain how to set the engine at overlap and look at the lifters to see if it’s even close, but I’ve typed that out before and I don’t want to do it again.
That will tell you if it’s close, but not where it’s at.