66 rear end identification ?

[Bruce L.]

I just pulled my rear pumpkin from my 66 today. The ID code is AM8 30 65. According to my references AM is 3.36:1 posi (small block), 8 is the month ( AUG.) and 30 would be the day. Is 65 the year? "Corvette by the numbers" by Alen Colven makes no reference to a year marking. They say that it should have a W at the end for Warren, Mich. Also they say that under the AM should be a posi. traction code E for eaton. The way I read it everything seems to make sense. My car has a birth date of Sept. 7 1965. Any of your expert help would be appreciated. Thanks, Bruce

[Wayne M.]

Colvin is describing '66 Chevrolets in general

And your interpretation of the coding is correct for 1966 (and at least through 1967 -- others may say when the Warren and Eaton coding came into use).

If you pull off the rear cover, there's also part #s, teeth ratios and dates on the ring gear and the end of the pinion gear. Good hunting.

[John H.]

Re: 66 rear end identification ?

Bruce -

There was a LOT of variation in how Warren stamped the diffs, even from day to day; some have the "W", some don't, some have the "E", some don't. Photo below is my '67 original "AM" 3.36 Posi - no "W", no "E" either. Yours sounds fine.

[Rick S.]

Re: 66 rear end identification ?

Here is my 67 3.36 posi made a couple weeks after John's.

[Bruce L.]

Thanks guys you are the best! NM *NM*