Differential code

[Christopher A.]

My quanta detail kit states that there should be a number written in grease pen on the top of my 66 differential. Does anybody know what the numbers should be for a 1966 427/390hp BB car with a 3.55posi rear?

Thanks

[Wayne M.]

Re: Differential code

My quanta detail kit states that there should be a number written in grease pen on the top of my 66 differential. Does anybody know what the numbers should be for a 1966 427/390hp BB car with a 3.55posi rear? ...

Can't say I've heard of nor seen the number (code ?) that you mention, although I'm not reall familiar with '66s.

But here's a code stamping 'AU' which is off a 12xxx VIN 1967 big block with 3.36 posi. This is on the top flange where it bolts to the rear cover. Notice they passed a grinder beforehand to make the stamp surface more visible. Next pic is of the bottom stampings which we're more familiar with.

Next two pics are top and bottom of my late 396. "FA" code is 3.70 posi for L78.

I don't know how much more identification would be necessay for final assembly purposes.