SS, cool down.
I thought it was very simple. The question that arose here, whether BMW specs are right or not, will not be answered by talking. How could it?
This simply takes some work: timing a 336.
Now, who could do that?
Know anyone having such a cam in his engine?
And having the skills and knowledge .....
Now, if you doubt the specs, then measure and prove they're wrong.
What's so difficult to understand about that?