I am struggling to find the code on my differential on a 70 SS. There are layers of paint and grime. In books I have seen that is on the tube on the drivers side of the car. Is it toward the front or the back of the car? Is it closer to the wheel or the gears?

http://www.chevelles.com/years/70/70rearcodes.html

Mine was closer to the gears and facing the front, just a little above midline of the axle.

hy mike532 do you have that info for a 69 chevelle.i to cannot find any info on my rear 12 bolt. thanks.

Same site.
http://www.chevelles.com/years/69/69rearcodes.html

Looks to me like that page shows the wrong spot for the stamped code.

At least the ones I've seen were on the FRONT of the passenger's side axle tube about midway between the wheel and pumpkin.