Using a feeler gauge one literally feels the drag between two surfaces. a .020" gauge didn't drag and a .021" did. So since we should use the Metric System here that converts to .53 mm. On finely polished surfaces one can feel .001" You need to use brass gauges to do this but they're pricey and don't last long. So was it exactly .53mm well no. It was between .020" and .021"

The real purpose of my post was to check my rational on the dishing. I'm glad this is more than enough as I spent 2 hours to get it like this but I learned alot. Thanks for the replies.