How do I measure this datum location?

I have 6 cored holes with draft on bolt circle. 2 of them are datums B & C. The other 4 are toleranced as normal.
The 2 datum cores have a datum target point or points inside them, at a basic height off the Datum A face. (One core is round, the other oblong)
I am wondering how to measure the size of the cores - we usually just use a plug gage, but do I need to taper it for a go/no go at this line? (like a gauge line)? I can attach a print view of one.
Thank you!

Welcome to the EE!

It would be better if you posted an image of the geometry and dimensional specification.

Thanks for replying Kelly. That is the detail for this core. Only other place shown on the print is the main veiw showing the bolt circle.

I am new to the forum. Where you able to view the print detail of the core? I did attach it. I do not see it as attached, but it appeared I did it correctly :)

[ATTACH=CONFIG]890[/ATTACH]Tried again, here it is!

QEng, to measure do one the following:

1) Use a micro-height or equivalent with the right length stylus to measure the size at the specified location. Then measure the angle - measure at several locations.

2) CMM - nothing more to say here, easy money.