I have a 70 Chevelle SS 454 and need help with rear decoding.After a few hours of cleaning i found on the passenger tube about 8" from housing
CRV and the letter E below it.There were no other numbers after these.On the driver side lower inner housing i found a casting number 3969278.
My build sheet shows GY2 for 3.31 axle and G80 for positraction
Any help would be appreciated

CRV is a '70 Chevelle 3.31 Posi 12 bolt
E=Eaton Posi

(edit)There should have been the assembly date stamped after CRV. They were hand stamped so out of alignment is possible. You can find the cast date which includes the year on the cover side of the center section. Will be very small "raised" letter for month and numbers for day and last digit of year cast. Look in the 5 or 7 o'clock position.

Rene
66_Malibu

Thanks Shooter ill check the date casting tomorrow. Any idea about the casting number
3969278...