Diff oil choices

[SoulSurvivor]

Just finished off the swap of the 7-1/4 to a 8-3/4, Mopar SS leafs and a new driveshaft. What is the preferred gear oil for the differential with Richmond gears and sure grip? I would like to use a synthetic with the sure grip additive already in it. Thanks,

Doug

 

[chasduster]

call the dealer....seems like just reg 80-90w..with whale sperm..oh sorry sure grip additive....shouldn't matter what gears ya have