rear end help

[7duster4]

I've got some questions regarding the 8 1/4 under my duster. I recently purchased a set of 3.21 gears and a limited slip for it. I called a local shop that does rear end work to get an estimate for the labor if I supplied the parts. He said I may need to buy more parts. He isn't sure whats inside the differential as far as shims and setting it up. My question is are the gears and limited slip all I need to replace the 2.76 thats currently in it? What else do I defiently need to make this work. I don't know much about rear ends and I just wanted something better then what was in it. Also what kind of oil do I need to get. And don't I need somekind of limited-slip additive.

Any information is greatly appreciated. Thanks

 

[69 Valiant Kid]

if you dont have green bearings on your axles you will need the shims. not sure where to get those because i have green bearings...i have an 8 3/4 with 3.91's and i use 75w140 with 2 4 oz bottles of friction modifier...mopar parts store should have that...any other help pm me...

 

[74fldart]

the mechanic may be hinting around about needing new pinion and carrier
bearings and a crush sleeve for sure and gasket. i would guess they would charge around $250.00 for the work.