Be sure to check out Paul Winchester's Tech article on this topic in the Quail Call this month.
White Wall Tires; The Black & White Truth of Model A Ford Shoes
by A Model A
What motor oil is best in a Ford Model A? What about zinc? ZDDP?
by Paul Shinn
What motor oil should you use for a Ford Model A? Do you need zinc? What about non detergent oil? This video will answer your motor oil questions for your Ford Model A.