now that the weather is breaking im geting ready to install the 9 bolt i purchased last year. wanted to double check a few things before hand. how much and what viscosity gear oil should i run and what/how much posi additive should i run?

 

75W90 or 80W90 gear oil, about 2 quarts. One bottle of GM or Ford oil additive. I actually recommend the Ford additive for this one because it is a cone type posi. Sometimes these require more than one bottle of additive. If it chatters and pops when you turn then you might want to add the second bottle.