what rear end gear oil to use

changing the rear pot on the Cuda, what gear oil should I use,
also it bunny hops around corners(what friction modifier should I use.
Thanks Dave

OK Let me know if this works,
80W90 2 1/2 to 3 quarts(litres up here)
GM friction modifier 1 to 2 bottles
1 bottle of Havana Club Rum (for the sore back after)

I use 75w90. As far as the friction modifier you can't go wrong with the FORD offering at their dealerships. It's the same (or extremely similar) to what Mopar used to sell, but no longer does.

Sounds like you have a power lock (clutch type) vs. a cone type, that's good.

80W90 or 75W90 sound good. I use the GM spec friction modifier from AZ with good results. One full tube.

Put a bottle of chrysler 4318060 additive in the dana 60 in my challenger today. Eliminated the noisy, rough feeling when turning tight curves in a parking lot.

I think doc diff recommends 85w140 conventional with the ford FM. I used Torco RGO 85w140
But I'm sure most any fluid will be fine.