Found 2 numbers on the lower "ribs" of the differential housing. Not the axle housing or tubes.

I can't find any information about these numbers. BTW this rearend is currently in a 66 Chevelle SS.

3894938N and GM10

I found CB1115B on the passenger side axle tube and know this means 3.36 gears assembled on 15 Nov of some year.

Any info would be appreciated.

Thanks

Used 1966 thru 1969. Need to find date code on housing to narrow it down.

http://www.camaros.org/rearaxlecastdate.gif

Only the 1965 housings which had additional webs on the top sides of the center section had the casting date in the location shown. 1966 and later had the casting date on a web on the lower left side of the center section.

3894938N should be the casting number for a 1967 10 bolt. It might be correct for a 66 if it was built late in the year, but any SS should have a 12 bolt (casting number 3894939N for 1967 and 3875745N for 1966), not a 10 bolt, so I don't think the rear is original to the car (assuming the car is really an SS). And the November 15 (1966) assembly date would indicate a mid model year 1967; too late to have been installed in a 66.

AZ Camino, According to the VIN and Trim she's a SS alright (13817 on both) and an early built one. So yes that 15 Nov assembly date threw me off as well. I figured as much. My guess is the original rear was swap out with this 10 bolt early in it's life. It's obvious this rear has been in the car a very long time.

Mike thanks for that drawing. I has seen something simular before but it wasn't clear as to whether the numbers were on the back or front. Your drawing is much better I appreciate it.

Thanks alot guys.