Trying to determine what diff is in my 65 Lark. It's a 10 bolt, but I'd like to determine the gearing. There appear to be no markings on the bottom of the pumpkin that I can see (see image 1 and 2 below). I can only make out what appears to be "C39" on the passenger side axle close to the pumpkin. According to my references there is no such number for Buick. Help please! ou: Thanks!!
Sorry, my info only goes back to 66. How many ribs on the side of the diff, and are they parallel, or do they converge?
