Distributor Housing to Intake Bore Clearance

[hotrod1442]

Does anyone have a BBC intake manifold handy that can take a measurement of the distributor hole bore size?

The intake manifold that I'm working with (early Olds DRCE-1 cast intake), just has a oval shaped opening where the distributor enters the manifold. I'm machining a "puck" to fill in this area to accept the distributor shaft. I'd like to get the proper bore size/clearance while I have it setup in the mill.

Thanks, Dave