Thanks Gary. Those write ups are excellent sources of information . They cover a lot of stuff , all in one convenient  location.  I will print those out and then try to remember where I stored them ! ...................................MO
On Wednesday, July 12, 2017 at 8:54:36 AM UTC-5, 62-65-mail...@xxxxxxxxxxx wrote:
See these write ups:
http://www.wichitamopar.com/wp-content/uploads/2012/10/MOPAR-REAR-DIFFERENTIAL-INFORMATION.pdf
http://www.mopar1.us/875.html
Gary H. 
>  -------Original Message-------
 
>  
>  Thanks, I appreciate that info. .. The question came up today--when
>  did the 489 differential come into use, and what on?  And, weren't all
>  of those the cone type sure lock? ...........................MO
>