Bellhousing alignment

[J&S Racing]

Ok, I’ve watched a few videos on the process and there seems to be 2 way to do it... I went with zeroing out at 12 o’clock and taking reading from 3/6/&9

After playing with the offset dowels I come up with this;


My question....is the run out 1/2 the dial reading??
So am I 8 or 4 thousand out??