Can anyone here tell the year model (rear end) need new seals)

Well I did some digging and I sure am glad I like the 2.45:1 hwy gear becouse I found this on the interweb, Units with a 2.45:1 gear ratio have a special case that will not accept any other gear ratio. The axles are retained by a c-clip on either side. All axles were 27 spline until 1997 when they were upgraded to 29 spline. I better pull the bearings and seals and take them to NAPA or other and let them get the #'ers off of them I guess.