Actually, looking at the flywheel it appears to me that it's exactly 30° out from that diagram...
Is it possible that 143-tooth flywheels were drilled on that different axis? Mine is a 143-tooth.
IIRC the 143 tooth is a truck flywheel and has a different drilling pattern. But don't take that as gospel, when I was contemplating this, it was with a 130 tooth flywheel.
"We live in a time when intelligent people are being silenced so that stupid people won't be offended".