what fluid for 8-3/4 sure grip?

[MrBelvedere2]

I would like to change the fluid in my 8-3/4 sure grip as i just got the car and have no idea when it was changed last, neither did the guy i got the car from. It's 3.23 gears and i'm not sure if it's cone or clutch type. Do you need to use different fluid depending if it is a clutch type or cone type? and if not what fluid do you guys use and recommend? how much do you put in?

 

[cosgig]

OE fluid was 80/90, although nowadays there are a lot of synthetics out there that may suit the job better. One thing that will not change is the fact that for a sure grip you will need a small bottle of friction modifier, usually on the shelf near the gear lube!! One bottle per customer please!!! Good luck with the project, Geof