Quote:

What size tires did the 40's cars run stock? 6.00-16s?



On the Plymouths that's right
http://www.allpar.com/history/plymouth/1940.html
"Standard tire size was 6.00x16" although 20" wheels were optional for rural mail carriers and others that required extra clearance." That's right, DUBS!

Yopu can also go to the Coker site and find OE sizes
http://store.coker.com/search.php?in_cat..._utmk=217521686


Dodge pages
http://www.allpar.com/cars/dodge/dodge-cars.html
http://auto.howstuffworks.com/1940-1948-dodge.htm