OK, I was wrong. I should have looked it up. I thought there was a 9.5º difference between the A and B front covers.
Apparently Model B base timing is 19º with minimal distributor advance totaling 36º.
http://www.fordgarage.com/pages/bdistributoradvance.htm
I know in 'more modern' cars I don't want base timing any more than 12º for kick back reasons.