Good 'Day All,

I purchased a set of 45 cases that have been welded, machined and what I thought was ready to go to build a 45 magnum engine, however the cylinder bolt pattern do not match the early sportster cylinders I have. Below is a picture of the bolt hole pattern the was installed.
Can anybody tell which bolt pattern I have?
Disregard the actual gasket pictured as it was only used for illustration purposes, and measurments.
Cylinder base gasket measurements.jpg

Any help would be greatly appreciated.

Thanks Brian