Boring out 3 brg crankcase for 2 brg crank

[Austin in the Shed]

Thanks for the reply Robert.
In the end I measured a two bearing case,well the thickness of the aluminum casting surrounding the bearing sleeve and took that away from the crank / cam centres and got a similar figure to you.
I did speak to Vince for his advice which was very helpful,I’ve never machined one out before in thirty odd years.I’ll post a picture of the set up of how it was done when in the workshop.