[fixitman1]

Rear axel housing Numbers 6 B H C 289 -1 came out of a el camino ? not sure what year ..:dontknow:

 

[oldtinsmith]

I got this info from "The catalog of Chevelle, Malibu & El Camino ID Numbers 1964-87" :
6BHC289-1

6BH is a 2.29 (posi from 1978-84 and non-posi from 1985-87)
C assembly plant is Buffalo
289 day of year
1 shift { 1st (?) (my book only indicated D & N for day & night)}

Doug