docent

Is there any stamp on the housing, to determine what the gears are in the 3rd member?

65GGvert

On what?

Vet65te

The differential housings were stamped on the bottom near the bolted cover. If no one has been into the diff to change gear sets, then you should be able to read the stampings and figure out what you have.
This is the '68 diff that's in my 65 Coupe. It's an AT code for 3:08 posi.

Mike T.

62Jeff

The stamp will tell you what gear ratio was in that case originally.

This is not a confirmation of what is in the case now.

docent

I'm Polish, so bear with me - - - -I see the AT code stamped on the
rear, as seen in the picture, but how do you get 3:08 from those numbers?

65GGvert

It seems for some reason you don't want to give your car or year, so take a look at these and pick what you want.

http://home.comcast.net/~jmasperi/vetrears.htm

docent

Thanks - - - that's it.

Joe Inama

Count teeth on ring gear and divide by the teeth on pinion.

65 Pro Vette

jack up the back, turn the wheel 1 revolution, as you do that count how many times the drive shaft turns. 3 1/8= 3.08. 3 1/2= 3.55. 3 3/4= 3.73. 4 1/8= 4.11. 4 1/2= 4.56