I finally got to take off my cover of my rear end on my 69 skylark and the #'s on the ring gear are. 14A 39 GM PD 248 It's a 12 bolt, Does that make it a canadian and a 8.5?
If I read it right, you have a 14 tooth pinion and a 39 tooth ring gear. That means you have a 2.78 to 1 ratio. Perfect for high speed runs though Death Valley
Tom is correct olds 12 bolt this is made in American oldsmobiles They can fit up under any Abody GM car from 1967-1972 and even the 64-66 being 1/2" wider on each side. Parts for this rear are very hard to come buy and the only 2 gear ratios made for this rear are 3.42 3.90...there was a 4.10 but I think that is gone now too. Posi units are not available unless your going to use a modified 8.8 ford unit. carrier breaks are 2.56 / 2.78 -3.23 / 3.42- 4.33 and beyond
