Hey guys, I have a stock 65 skylark GS auto car that has a posi in it with a 3.42 gear in it [as near as I can tell] Is this a 10 bolt or a 12 bolt? o No: o No: o No:
Depends on where it was built.. All American cars had standard a 10 bolt. Canadian cars required a 12 bolt rear. You can see what rear it is by looking on the bottom of the driver side tube for 2 letters stamped there. Here's the chart for the ratio numbers. :TU: PHP: 65-67 Rear Axle Chart Axle Ratio 3000/4000 Series* Std Axle Posi Axle 2.56 LK LV 2.78 LA LN 2.93 OB OW 3.08 LB LO 3.23 LC LP 3.36 LD LR 3.55 ----- ON 3.90 ----- OO